• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 16
  • 15
  • 13
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 55
  • 10
  • 9
  • 9
  • 7
  • 6
  • 6
  • 6
  • 6
  • 6
  • 6
  • 6
  • 6
  • 5
  • 5
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

CARDIAC AND RESPIRATORY AUSCULTATION SKILL DEVELOPMENT: EXPLORATION AND APPLICATION OF COGNITIVE LOAD THEORY IN HEALTH PROFESSIONS EDUCATION

Chen, Ruth 10 1900 (has links)
<p>This thesis explores the Cognitive Load Theory (CLT) framework with health professions education research, and applies the principles of CLT to one specific area of health professions education: the acquisition of cardiac and respiratory auscultation and physical assessment skill in undergraduate nursing students. The first study evaluates context-based learning environments on the acquisition of auscultation skill and physical assessment performance. Results suggest that for novice level students, high-context-based learning environments may contribute to extraneous cognitive load and may not be beneficial for learning. The next cluster of studies evaluates auscultation test performance following manipulation of cognitive load variables. The interleaving approach instruction was found to be most helpful for auscultation test performance. The series of studies conducted in this thesis demonstrate a useful direction for health professions research and promotes the use of cognitive load theory as a framework for instructional design and evaluation.</p> / Doctor of Philosophy (PhD)
32

Comportement thermo-mécanique de structures de chaussées bitumineuses / Thermomechanical behaviour of bituminous pavement structures

Gaborit, Philippe 19 June 2015 (has links)
Cette thèse CIFRE a été réalisée dans le cadre d'un partenariat entre l'ENTPE Université de Lyon, AREA et EIFFAGE Travaux Publics. Les méthodes actuelles de détermination et de prévision de l'endommagement des structures de chaussées autoroutières sont peu fiables et nécessitent d'être améliorées. L'objectif de la thèse est de mettre en place une procédure d'analyse inverse donnant accès aux paramètres de comportement des matériaux de chacune des couches de chaussées à partir des mesures de déflexion. Une première étape vise à définir plus précisément les états de contraintes et de déformations existants dans les différentes couches de chaussées. Pour cela, une instrumentation de chaussée autoroutière située proche d'Aix les Bains a été réalisée. 47 capteurs de déformation et de température ont été implantés dans la structure à trois niveaux différents lors de travaux d'entretien effectués en août 2012. En parallèle, des matériaux de chaussée ont été prélevés sur autoroutes pour caractériser leur comportement en laboratoire. Des essais de module complexe ont permis de déterminer les propriétés thermo-visco-élastiques des matériaux. Ces résultats ont permis de modéliser la déformation de la chaussée et de la comparer avec les mesures. Des mesures de déflexion ont également été réalisées sur la chaussée instrumentée à l'aide d'un curviamètre. Les résultats ont pu être comparés à la modélisation. Les différences observées ont permis de proposer une analyse critique des mesures de déflexion. / This thesis was conducted into a parnership between ENTPE university of Lyon, AREA and Eiffage Travaux Publics. Current methods of determination and prediction of damage to highway pavement structures are unreliable and need to be improved. The aim of the thesis is to establish an back analysis procedure from the deflection measurements fiving access to material behavior parameters of each pavement layers. A first step is to define more precisely the states of stress and deformation existing in the different layers of pavement. For this reason, a motorway pavement instrumentation was performed near Aix les Bains in France. 47 strain sensors and temperature were implanted into the structure in three layers during maintenance works in August 2012.In parallel, pavement materials were collected on motorways to characterize their behavior. Complex modulus tests were used to determine the thermo-viscoelalstic properties of materials. These results were used to modeling the deformation of the pavement and compared with measurements. Deflection measurements were also performed on the instrumented pavement with a curviameter device. The reseults were compared to modeling. The observed differences have helped to provide a critical analysis of deflection measurements.
33

Assessing the structural elements of reinforced concrete buildings by using dynamic measurements / Caractérisation d'éléments structurels en béton armé par mesures dynamiques

Sentosa, Bastian Okto Bangkit 27 September 2018 (has links)
Les applications des mesures dynamiques sur les bâtiments existants sont nombreuses : vérification de la vulnérabilité sismique des structures qui ont été construites avant l’apparition des règles parasismiques ; auscultation de la capacité des structures en situation post-sismique ou après des modifications au voisinage (creusement d’un tunnel à côté ou démolition des immeubles voisins par exemple). A l’heure actuelle, ce type de mesure permet le diagnostic d’une structure à l’échelle globale (toute la structure) alors que l’identification et la localisation des endommagements à l’échelle locale (chaque élément de la structure) restent encore à approfondir. Dans le cadre de cette thèse, le diagnostic à l’échelle locale des structures sera étudié. Cette thèse s’insère dans un contexte national de réévaluation des structures existantes du fait du nombre important de bâtiments à réhabiliter. Au sein du LOCIE, nous pensons que le comportement global des bâtiments est certes influencé par l’interaction sol-structure mais au moins autant par la qualité des connexions des éléments de structures entre eux. Il existe un besoin de qualification de ces connexions dont la variabilité du comportement peut provenir aussi bien de défauts de mise en œuvre (positionnement des armatures,…) que du vieillissement des structures. L’objectif principal de cette thèse est de proposer une méthode pouvant caractériser les liaisons entre les éléments de structure afin de pouvoir caler un modèle numérique. Ces caractérisations devaient être possibles à partir de mesures de sollicitations dynamiques. Une première étape de ce travail consistera à caractériser sur une partie de structure une liaison. Cela sera fait sur un portique en béton armé. Par la suite, cette méthode sera adaptée à une caractérisation au sein d’une structure de bâtiment. Pour cela nous ferons appel à la notion de sous-modèle. Un modèle numérique sera associé à cette méthode aussi bien sur la connexion simple que sur l’ensemble du bâtiment. Le travail de thèse s’appuiera sur l’utilisation et le développement de techniques concernant le traitement des données dynamiques ; la réduction de modèles ; l’expérimentation en laboratoire (échelle locale et échelle d’un élément de structure) et la modélisation numérique par éléments finis à plusieurs échelles / There are many of the examples of dynamics measurements applications in the existing building: verification of structural seismic vulnerability, which was constructed before the earthquake building code; auscultation of structural capacity in post-earthquake situation or after modification in surround environment (Excavation of tunnel or demolition the neighbour buildings for example). Currently, this measurement type enables the diagnosis a structure in global scale (a whole structure) while identification and localization of damage in local scale (each elements of the structure) remains to be explored. In this dissertation, diagnosis in locale scale will be studied. This study is significant for its contribution to the national reassessment of existing structures where there is the large number of buildings to be rehabilitated
34

Segurança de barragens de concreto : auscultação por instrumentação da barragem da UHE Dona Francisca-RS

Santos, Verlei Oliveira dos January 2018 (has links)
Este trabalho aborda a temática de segurança de barragens de gravidade e apresenta uma metodologia para análise por instrumentação colocada no maciço destas estruturas. Como estudo de caso, utilizou-se a barragem da Usina Hidrelétrica de Dona Francisca, construída no final do ano de 2000, no Rio Jacuí, na região central do Estado do Rio Grande do Sul, Brasil. Sua estrutura é de concreto compactado com rolo e possui cerca de 63 metros de altura máxima e 660 metros de comprimento. As condições geológico-geotécnicas da fundação da UHE Dona Francisca remetem às rochas da Formação Caturrita, constituídas principalmente por arenitos e níveis de siltito e argilito intercalados. Devido à preocupação com o comportamento deste tipo de fundação em relação à estabilidade das estruturas, a UHE Dona Francisca foi contemplada com um amplo plano de instrumentação, composto principalmente por medidores de vazão, piezômetros, pêndulos diretos, extensômetros e medidores triortogonais de junta. Esta dissertação apresenta e analisa os dados destes dispositivos. Os objetivos principais foram avaliar a evolução dos registros ao longo do tempo e frente às variações de carregamento e condições ambientais, além de comparar as leituras com as previsões de projeto e com os dados de instrumentação de outras barragens. Observou-se que a maioria da instrumentação é sensível à variação do nível do reservatório e, portanto, o mesmo foi tomado como referencial nas apresentações das leituras dos instrumentos. De um modo geral, a barragem esteve estável durante o período auscultado de 17 anos. As poropressões foram controladas satisfatoriamente pelo sistema de drenagem. Na maioria das vezes, os deslocamentos, as deformações na fundação e vazões foram superiores aos registros de outras barragens de maior porte. Entretanto, essas grandezas tenderam a reduzir ou se estabilizar ao longo dos anos. Atualmente, alguns instrumentos exigem atenção visto que suas leituras não estão estáveis ou não correspondem às previsões de comportamento estabelecidas durante a fase de projeto. A metodologia para análise adotada neste trabalho mostrou-se eficaz e permitiu a definição das tendências atuais de leituras de cada instrumento. / This work deals with the safety of gravity dams and presents a methodology for analysis by instrumentation inserted in the massif of these structures. The Dona Francisca Hydroelectric dam was used as a case study. This dam was built in the end of 2000, on the Jacuí River, in the central region of the Rio Grande do Sul State, Southern Brazil. Its structure is made of rolled concrete and has approximately 63 meters of maximum height and 660 meters in length. The geological and geotechnical conditions of the Dona Francisca HPP foundation refer to the Caturrita Formation rocks, made up mainly of sandstones and intercalated levels of siltstone and claystone. Due to the concern about the behavior of this type of foundation in relation to the stability of the structures, the Dona Francisca HPP was contemplated with a broad instrumentation plan, composed mainly of flow meters, piezometers, direct pendulums, extensometers and triorthogonal meters. This dissertation presents and analyzes the data of these devices. The goals were to evaluate the evolution of these registers over time and in relation to loading variations and environmental conditions, moreover, compare the readings with the project forecasts and the instrumentation data from other dams. It was observed that most of the instrumentation is sensitive to variation of the reservoir level and, therefore, it was taken as reference in the presentations of the instruments readings. In general, the dam of the Dona Francisca HPP was stable during this auscultated period of 17 years. The pore water pressures were successfully controlled by the drainage system. Most of the time, the displacements, the deformations in the foundation and flows were higher to the records of other larger dams. However, these magnitudes have tended to decrease or stabilize over the years. Nowadays, some auscultation devices require attention because their readings are not stable or do not match the behavior predictions established during the design stage. The analysis methodology adopted in this study proved to be effective and allowed the definition of each instrument reading trends.
35

Auscultation dynamique des structures à l'aide de l'analyse continue en ondelettes

Le, Tien-Phu 11 1900 (has links) (PDF)
On étudie l'application de l'analyse continue en ondelettes à l'auscultation dynamique des structures à partir des réponses transitoires sous excitations imparfaitement connues (choc, ambiante...). L'outil numérique de la transformation continue en ondelettes est établi. Il est fondé sur l'ondelette mère (Morlet ou Cauchy) et sur un paramètre la caractérisant: le facteur Q de qualité du filtre. Il permet d'extraire les amplitudes et les fréquences instantanées contenues dans le signal. Un domaine du plan temps-fréquence où l'effet de bords est négligeable, et un encadrement de Q sont déterminés. Le traitement du signal réel modulé en amplitude et en fréquence par l'outil proposé facilite l'identification modale des structures (linéaires et non-linéaires) et permet une amélioration de la méthode impact-écho. Une procédure adaptée à chaque application est détaillée. Les résultats obtenus à partir des tests numériques et réels montrent l'efficacité de la méthode.
36

Nonlinear phonocardiographic Signal Processing

Ahlström, Christer January 2008 (has links)
The aim of this thesis work has been to develop signal analysis methods for a computerized cardiac auscultation system, the intelligent stethoscope. In particular, the work focuses on classification and interpretation of features derived from the phonocardiographic (PCG) signal by using advanced signal processing techniques. The PCG signal is traditionally analyzed and characterized by morphological properties in the time domain, by spectral properties in the frequency domain or by nonstationary properties in a joint time-frequency domain. The main contribution of this thesis has been to introduce nonlinear analysis techniques based on dynamical systems theory to extract more information from the PCG signal. Especially, Takens' delay embedding theorem has been used to reconstruct the underlying system's state space based on the measured PCG signal. This processing step provides a geometrical interpretation of the dynamics of the signal, whose structure can be utilized for both system characterization and classification as well as for signal processing tasks such as detection and prediction. In this thesis, the PCG signal's structure in state space has been exploited in several applications. Change detection based on recurrence time statistics was used in combination with nonlinear prediction to remove obscuring heart sounds from lung sound recordings in healthy test subjects. Sample entropy and mutual information were used to assess the severity of aortic stenosis (AS) as well as mitral insufficiency (MI) in dogs. A large number of, partly nonlinear, features was extracted and used for distinguishing innocent murmurs from murmurs caused by AS or MI in patients with probable valve disease. Finally, novel work related to very accurate localization of the first heart sound by means of ECG-gated ensemble averaging was conducted. In general, the presented nonlinear processing techniques have shown considerably improved results in comparison with other PCG based techniques. In modern health care, auscultation has found its main role in primary or in home health care, when deciding if special care and more extensive examinations are required. Making a decision based on auscultation is however difficult, why a simple tool able to screen and assess murmurs would be both time- and cost-saving while relieving many patients from needless anxiety. In the emerging field of telemedicine and home care, an intelligent stethoscope with decision support abilities would be of great value.
37

Att lyssna på sväljning : En studie om användning av cervikal auskultation vid bedömning av dysfagi i Sverige

Berglund, Viktoria, Engström, Carin January 2013 (has links)
Syftet med denna studie var att undersöka hur användningen av bedömningsmetoden cervikal auskultation (CA) ser ut hos dysfagilogopeder i Sverige. Våra frågeställningar var: Hur utspridd är metoden inom logopedkåren? Hur utspridd är metoden i landet? Vilka åsikter finns kring metoden bland logopeder i Sverige? Vilka undersökningsmetoder vid dysfagi används mest bland logopeder i Sverige? Totalt deltog 82 personer i studien. Data samlades in genom en webbenkät. Frågorna i enkäten var blandat öppna och slutna. Resultaten visade att 18 % av de svarande använde CA. Det fanns ett signifikant samband mellan hur ofta man använde metoden och hur säker man kände sig i bedömningen. Signifikans hittades också mellan hur ofta man använde CA och hur stor vikt man lade vid det man kom fram till med metoden när man gjorde sin totala bedömning. Större vikt tillskrevs även CA:s resultat av dem som kände sig säkra i att bedöma med CA. Resultaten visade också att ju fler år man hade använt metoden desto säkrare kände man sig i att göra bedömningar med den. Majoriteten av de som använde CA var självlärda eller hade lärt sig metoden genom kollegor. En tanke som uppkom var om logopeder i Sverige eventuellt tror att CA är menat att användas som enskild bedömningsmetod och därmed ersätta icke-instrumentell bedömning. CA tycks inte användas så frekvent i Sverige främst på grund av brister i evidens och tillförlitlighet men många ser fördelar som skulle motivera användning av CA som en del i icke-instrumentell bedömning. / The purpose of this study was to investigate the use of the assessment method cervical auscultation (CA) amongst speech and language pathologists (SLPs) in Sweden working with dysphagia. We wanted to find out: How widespread is the method in the SLP profession? How widespread is the method in the country? What opinions are there about the method amongst SLP´s in Sweden? What assessment methods within dysphagia are mostly used among SLP´s in Sweden? A total of 82 SLPs participated in the study. Data were collected through an online survey. The survey questions were of both quantitative and qualitative nature. The results showed that 18% of the respondents used CA. There was a significant correlation between the frequency of use of the method and how confident SLPs felt in the assessment. Significance was also found between the frequency of use of CA and how much importance SLPs assigned to what was discovered with the method when making the overall assessment. More importance was also ascribed to the results of CA from those who felt confident in assessing with the method. The results also showed that the longer SLPs had used the method, the more confident they felt in assessing with it. The majority of those who used CA were self-taught or had learned the method through colleagues. A thought that arose was whether the SLPs in Sweden possibly believe that CA is meant to be used as the sole method of assessment, replacing non-instrumental assessment. CA does not seem to be used frequently in Sweden, mainly because of lack of evidence and reliability but many see benefits that would justify the use of CA as part of the clinical assessment.
38

Détection et évaluation des fuites à travers les ouvrages hydrauliques en remblai, par analyse des températures réparties, mesurées par fibre optique

Cunat, Pierre 08 March 2012 (has links) (PDF)
Les fuites au travers des ouvrages hydrauliques en remblai sont les signes précurseurs d'un dysfonctionnementdu dispositif d'étanchéité de l'ouvrage pouvant entraîner leur rupture. La détectionprécoce des fuites et leur quanti_cation est donc primordiale.Les méthodes géophysiques et thermométriques à grand rendement apportent des éléments deréponse pour la détection des fuites, le long des ouvrages à long linéaire, mais l'estimation de leurvitesse, nécessaire à l'évaluation de la dangerosité des fuites, n'est pas encore satisfaisante.Cette étude porte sur la détection et quanti_cation des fuites à travers les ouvrages hydrauliquesen remblai soumis à une charge d'eau permanente. Les méthodes proposées exploitent des mesures detempératures naturelles du sol à l'aide de _bres optiques placées sous le talus amont ou aval.Deux modèles de quanti_cation ont été développés et testés sur les données d'un site expérimentalcontrôlé et d'un site réel. Les résultats obtenus concordent avec les mesures de vitesse e_ectuées surles deux sites.
39

Détection et évaluation des fuites à travers les ouvrages hydrauliques en remblai, par analyse des températures réparties, mesurées par fibre optique / Use of temperature measurements as a monitoring tool for earthen hydraulic structures, leakage detection and estimation of their intensity.

Cunat, Pierre 08 March 2012 (has links)
Les fuites au travers des ouvrages hydrauliques en remblai sont les signes précurseurs d'un dysfonctionnementdu dispositif d'étanchéité de l'ouvrage pouvant entraîner leur rupture. La détectionprécoce des fuites et leur quanti_cation est donc primordiale.Les méthodes géophysiques et thermométriques à grand rendement apportent des éléments deréponse pour la détection des fuites, le long des ouvrages à long linéaire, mais l'estimation de leurvitesse, nécessaire à l'évaluation de la dangerosité des fuites, n'est pas encore satisfaisante.Cette étude porte sur la détection et quanti_cation des fuites à travers les ouvrages hydrauliquesen remblai soumis à une charge d'eau permanente. Les méthodes proposées exploitent des mesures detempératures naturelles du sol à l'aide de _bres optiques placées sous le talus amont ou aval.Deux modèles de quanti_cation ont été développés et testés sur les données d'un site expérimentalcontrôlé et d'un site réel. Les résultats obtenus concordent avec les mesures de vitesse e_ectuées surles deux sites. / Leakages through embankment dams are early warning signs of a sealing malfunction and couldlead to its breakdown. Early detection of leakages and their quanti_cation is essential.High output geophysical and thermometric methods provide some answers for leakage detectionalong long linear embankment dams, but their velocity estimations necessary to assess the danger ofleakages, is not yet satisfactory.This study focuses on the detection and the quanti_cation of leakages through embankment damsunder hydraulic head. The proposed method use natural temperature measurements from the groundusing optical _ber buried under the upstream or downstream face.Two models of quanti_cation were developed and tested on data from an experimental site and a realsite. Results are consistent with velocity measurements made at both side.
40

Evaluation of functional cardiac murmur with echocardiography– a systemic quality work

Fredriksson, Ida January 2024 (has links)
Background: Valvular heart disease (VHS) can be lethal. An auscultated murmur could be a first indication of VHS. Lately auscultation has been evaluated as non-accurate, while a murmur also can be normal/functional. The next step of verifying VHS, is a transthoracic echocardiography (TTE). The echocardiography clinic at Uppsala University Hospital has seen a lot of non-pathological referrals regarding murmur evaluation. Therefore, a fast-track screening TTE, performed by a biomedical scientist was of interest. Aim: The aim was to evaluate pathological possibility, regarding remitted patients with a new heart murmur. Material: The clinical quality work was based on remitted patients of ages 18 to 50. Sampling took place between November 2022 and Mars 2024, by Radiology Information System. Method: Type of murmur, outcomes and referring clinic was documented. Normal outcome group consisted of: absent VHS and mild VHS. Pathological outcome group consisted of: moderate and severe VHS. Probability was calculated based on systolic- and non-specified murmur. Result: Normal outcome group had 116 referrals and pathological outcome group had three referrals. Possibility of a pathological outcome became 2,5 %. Majority of the referrals came from the primary care (92 %). Conclusion: A systolic- and non-specified murmur had low possibility of a pathological outcome, which could indicate that a shorter screening TTE by a biomedical scientist is an option. A limitation was that the type of the remitted murmur could not be trusted. Majority of the referrals came from the primary care, which indicates that further clinical work at these facilities is necessary.

Page generated in 0.0727 seconds