103 research outputs found

    VĂ©rification du logiciel CFX pour la simulation de l'interaction arc-Ă©coulement dans les disjoncteurs haute-tension.

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    RÉSUMÉ Le but du projet est de vĂ©rifier s’il est envisageable d’utiliser le code commercial CFX de ANSYS Inc. dans le but de simuler la coupure du courant dans un disjoncteur Ă  haute tension. CFX est un code de dynamique des fluides au sens large, avec des options disponibles pour simuler diffĂ©rents types de problĂšmes d’écoulements de fluides, en trois dimensions spatiales. La mĂ©thodologie utilisĂ©e est principalement une comparaison entre deux codes, et avec la solution analytique, lorsque la gĂ©omĂ©trie utilisĂ©e le permet. Le code utilisĂ© comme base de comparaison est MC3, qui est un code ayant dĂ©jĂ  Ă©tĂ© validĂ©, conçu spĂ©cialement pour simuler l’allumage et la coupure d’un arc Ă©lectrique dans une gĂ©omĂ©trie de disjoncteur haute tension, avec une approximation d’axisymĂ©trie de la gĂ©omĂ©trie. L’idĂ©e derriĂšre le projet est donc de passer d’une mĂ©thode de calcul en deux dimensions que l’on sait fonctionnelle, avec des approximations pour obtenir des conditions axisymĂ©triques, Ă  une mĂ©thode de calcul pleinement tridimensionnelle en terme spatial, diminuant ainsi le nombre d’approximations Ă  effectuer. Les concepts de vĂ©rification et de validation de codes sont expliquĂ©s, avec un rĂ©sumĂ© de certaines mĂ©thodes particuliĂšres. Une brĂšve description du fonctionnement des disjoncteurs haute tension est donnĂ©e, avec un rĂ©sumĂ© des principes physiques utilisĂ©s. Les Ă©quations physiques rĂ©solues par les solveurs sont donnĂ©es (dynamique des gaz, rayonnement, Ă©lectromagnĂ©tisme), avec un rĂ©sumĂ© qualitatif des modĂšles numĂ©riques utilisĂ©s. La gĂ©omĂ©trie et la physique des cas tests utilisĂ©s sont dĂ©crits, avec la solution analytique lorsque cela est possible. Les rĂ©sultats de ces cas tests sont analysĂ©s et comparĂ©s entre les deux codes et la solution analytique. Ces cas tests ont pour but de simuler des cas simples faisant ressortir sĂ©parĂ©ment chacune des caractĂ©ristiques physiques prĂ©sentes dans un disjoncteur haute tension. Les caractĂ©ristiques physiques d’importance sont donc vĂ©rifiĂ©es une Ă  la fois. Une tentative de calcul sur une situation un peu plus rĂ©aliste a finalement Ă©tĂ© effectuĂ©e.----------ABSTRACT The goal of the project is to verify the possibility of using ANSYS Inc.’s CFX commercial code for simulations of current interruption in a high-voltage circuit breaker. CFX is a fluid dynamic code in a wide sense, with available options for simulating many fluid flow problems, in three spatial dimensions. The method used for the verification is mainly a code to code comparison, and with analytical solutions, when the geometry allow it. The code used as comparison basis is MC3, which has already been validated. It is specially made for simulating ignition and cutting of electric arcs in a circuit breaker geometry, with an axisymmetric approximation. The idea of the project is to pass from a well validated two dimensional method, with axisymmetric approximations, to a fully three spatial dimensions method, decreasing the number of approximations to do. The code verification and validation concepts are explained, with a summary of some particular methods. A brief description of high-voltage circuit breakers operation is given, with a summary of physical principles used for its modeling. The physical equations solved by the computer codes are given (gas dynamic, radiation, electromagnetism), with a qualitative summary of numerical models used. The geometry and physics of test cases used are described, with analytical solution when possible. The results of theses test cases are analyzed and compared between the two codes and the analytical solution. The goal of theses test cases is to simulate simple cases showing separately each physical characteristics present in a high-voltage circuit breaker. The physical characteristics of importance are then verified one by one. An attempt on a more realistic and complex situation was finally done

    DĂ©coder les Ă©motions Ă  travers la musique et la voix

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    L’objectif de cette thèse est de comparer les mécanismes fondamentaux liés à la perception émotionnelle vocale et musicale. Cet objectif est sustenté par de nombreux rapports et théories appuyant l'idée de substrats neuronaux communs pour le traitement des émotions vocales et musicales. Il est proposé que la musique, afin de nous faire percevoir des émotions, recrute/recycle les circuits émotionnels qui ont évolué principalement pour le traitement des vocalisations biologiquement importantes (p.ex. cris pleurs). Bien que certaines études ont relevé de grandes similarités entre ces deux timbres (voix, musique) du point de vue cérébral (traitement émotionnel) et acoustique (expressions émotionnelles), certaines différences acoustiques et neuronales spécifique à chaque timbre ont également été observées. Il est possible que les différences rapportées ne soient pas spécifiques au timbre, mais observées en raison de facteurs spécifiques aux stimuli utilisés tels que leur complexité et leur longueur. Ici, il est proposé de contourner les problèmes de comparabilité de stimulus, par l’utilisation des expressions émotionnelles les plus simples dans les deux domaines. Pour atteindre l’objectif global de la thèse, les travaux ont été réalisés en deux temps. Premièrement, une batterie de stimuli émotionnels musicaux comparables aux stimuli vocaux déjà disponibles (Voix Affectives Montréalaises) a été développée. Des stimuli (Éclats Émotionnels Musicaux) exprimant 4 émotions (joie, peur, tristesse, neutralité) performés au violon et à la clarinette ont été enregistrés et validés. Ces Éclats Émotionnels Musicaux ont obtenu un haut taux de reconnaissance (M=80.4%) et reçu des jugements d’arousal (éveil/stimulation) et de valence correspondant à l’émotion qu’il représentait. Nous avons donc pu, dans un deuxième temps, utiliser ces stimuli nouvellement validés et les Voix Affectives Montréalaises pour réaliser deux études de comparaison expérimentales. D’abord, nous avons effectué à l’aide de l’imagerie par résonnance magnétique fonctionnelle une comparaison des circuits neuronaux utilisés pour le traitement de ces deux types d’expressions émotionnelles. Indépendamment de leur nature vocale ou musicale, une activité cérébrale spécifique à l'émotion a été observée dans le cortex auditif (centrée sur le gyrus temporal supérieur) et dans les régions limbiques (gyrus parahippocampique/amygdale), alors qu'aucune activité spécifique aux stimuli vocaux ou musicaux n'a été observée. Par la suite, nous avons comparé la perception des émotions vocales et musicales sous simulation d’implant cochléaire. Cette simulation affectant grandement la perception des indices acoustiques liés aux hauteurs tonales (important pour la discrimination émotionnelle), nous a permis de déterminer quels indices acoustiques secondaires à ceux-ci sont importants pour la perception émotionnelle chez les utilisateurs d’implant cochléaire. L’examen des caractéristiques acoustiques et des jugements émotionnels a permis de déterminer que certaines caractéristiques timbrales (clarté, énergie et rugosité) communes à la voix et la musique sont utilisées pour réaliser des jugements émotionnels sous simulations d’implant cochléaire, dans les deux domaines. L’attention que nous avons portée au choix des stimuli nous a permis de mettre de l’avant les grandes similarités (acoustique, neuronales) impliquées dans la perception des émotions vocales et musicales. Cette convergence d’évidence donne un appui important à l’hypothèse de circuits neuronaux fondamentaux commun pour le traitement des émotions vocales et musicales.The aim of this thesis is to compare the fundamental mechanisms related to vocal and musical emotion perception. This objective is supported by many reports and theories bringing forward the idea of common neural substrates for the treatment of vocal and musical emotions. It is proposed that music, in order to make us perceive emotions, recruits/recycles the emotional circuits that evolved mainly for the treatment of biologically important vocalisations (e.g. cries, screams). Although some studies have found great similarities between these two timbres (voice, music) from the cerebral (emotional treatment) and acoustic (emotional expressions) point of view, some acoustic and neural differences specific to each timbre have also been reported. It is possible that the differences described are not specific to the timbre but are observed due to factors specific to the stimuli used such as their complexity and length. Here, it is proposed to circumvent the problems of stimulus comparability by using the simplest emotional expressions in both domains. To achieve the overall objective of the thesis, the work was carried out in two stages. First, a battery of musical emotional stimuli comparable to the vocal stimuli already available (Montreal Affective Voices) was developed. Stimuli (Musical Emotional Bursts) expressing 4 emotions (happiness, fear, sadness, neutrality) performed on the violin and clarinet were recorded and validated. These Musical Emotional Bursts obtained a high recognition rate (M = 80.4%) and received arousal and valence judgments corresponding to the emotion they represented. Secondly, we were able to use these newly validated stimuli and the Montreal Affective Voices to perform two experimental comparison studies. First, functional magnetic resonance imaging was used to compare the neural circuits used to process these two types of emotional expressions. Independently of their vocal or musical nature, emotion-specific activity was observed in the auditory cortex (centered on the superior temporal gyrus) and in the limbic regions (amygdala/parahippocampal gyrus), whereas no activity specific to vocal or musical stimuli was observed. Subsequently, we compared the perception of vocal and musical emotions under cochlear implant simulation. This simulation greatly affects the perception of acoustic indices related to pitch (important for emotional discrimination), allowing us to determine which acoustic indices secondary to these are important for emotional perception in cochlear implant users. Examination of acoustic characteristics and emotional judgments determined that certain timbral characteristics (brightness, energy, and roughness) common to voice and music are used to make emotional judgments in both domains, under cochlear implant simulations. The specific attention to our stimuli selection has allowed us to put forward the similarities (acoustic, neuronal) involved in the perception of vocal and musical emotions. This convergence of evidence provides important support to the hypothesis of a fundamental common neural circuit for the processing of vocal and musical emotions

    Utilisation normale du mode et du tempo par les amusiques adultes, lors de jugements Ă©motionnels

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    Notre aptitude Ă  dĂ©terminer si un extrait de musique est gai ou triste rĂ©side dans notre capacitĂ© Ă  extraire les caractĂ©ristiques Ă©motionnelles de la musique. Une de ces caractĂ©ristiques, le mode, est liĂ©e aux hauteurs musicales et une autre, le tempo, est temporelle (Hevner, 1937; 1935). Une perception dĂ©ficitaire de l’une de ces caractĂ©ristiques (ex. les hauteurs) devrait affecter l’expĂ©rience Ă©motionnelle. L’amusie congĂ©nitale est caractĂ©risĂ©e par un traitement anormal des hauteurs (Peretz, 2008). Toutefois, peu de donnĂ©es ont Ă©tĂ© accumulĂ©es sur les rĂ©ponses Ă©motionnelles des amusiques face Ă  la perception du mode. La perception Ă©motionnelle liĂ©e Ă  celui-ci pourrait ĂȘtre prĂ©servĂ©e, chez les amusiques en raison de leur perception implicite des hauteurs (Peretz, et coll., 2009). Dans un premier temps, cette Ă©tude cherchera Ă  dĂ©terminer dans quelle mesure les amusiques adultes utilisent le mode relativement au tempo dans la distinction d’une piĂšce gaie, d’une triste. Dans cette optique, onze amusiques et leurs contrĂŽles appariĂ©s ont jugĂ© des extraits de musique classique gais et tristes, dans leur forme originale et dans deux versions modifiĂ©es : (1) mode inversĂ© (transcrit dans le mode opposĂ© mineur ↔ majeur) et (2) tempo neutralisĂ© (rĂ©glĂ© Ă  une valeur mĂ©diane), oĂč le mode Ă©merge comme caractĂ©ristique dominante. Les participants devaient juger si les extraits Ă©taient gais ou tristes sur une Ă©chelle de 10-points, pendant que leurs rĂ©ponses Ă©lectromyographiques (zygomatique et corrugateur) Ă©taient enregistrĂ©es. Les participants ont par la suite Ă©tĂ© rĂ©invitĂ©s au laboratoire pour rĂ©aliser une tĂąche non Ă©motionnelle de discrimination des modes (majeur, mineur), dans laquelle des paires de stimuli composĂ©s de versions plus courtes des extraits originaux et leur version au mode inversĂ© leur Ă©taient prĂ©sentĂ©es. Les participants (14; 7 amusiques) devaient juger si les paires Ă©taient identiques (mĂȘme stimulus, mĂȘme mode) ou diffĂ©rentes (mĂȘme stimulus, modes diffĂ©rents). Dans cette derniĂšre tĂąche, les amusiques ont eu plus de difficultĂ© que leurs contrĂŽles Ă  discriminer les modes, mais les amusiques comme leurs contrĂŽles se sont montrĂ©s sensibles aux manipulations du mode et du tempo, dans la tĂąche Ă©motionnelle. Ces rĂ©sultats supportĂ©s par des rĂ©ponses EMG normales prĂ©supposent des habiletĂ©s prĂ©servĂ©es ou implicites de traitement tonal dans l’amusie congĂ©nitale.Our ability to determine if a music piece is happy or sad depends on our capacity to extracts the main emotional characteristics of music. One of these characteristics, the mode, is a pitch based constituent, and another one, the tempo, is a temporal factor (Hevner, 1937; 1935). The inability to extract one of those characteristics (pitch) should affect the emotional experience. Congenital amusia is characterized by anomalous pitch processing (Peretz, 2008). Yet, little is known about the amusics’ emotional responses to mode. Perhaps emotional perception of this characteristic is preserved due to the amusics’ implicit pitch processing (Peretz, et coll., 2009). First, we decided to examine how amusic adults use mode relative to tempo in distinguishing happy from sad musical excerpts. To this aim, we tested whether eleven amusics and their matched controls judged excerpts of happy and sad classical music in their original form and in two manipulated conditions: the ‘‘inverted mode condition’’ where the excerpts were transcribed in the opposite mode (major↔minor); and the ‘‘neutralized tempo condition’’ where all tempi were set to the same median value, hence the mode emerges as the main emotional characteristic. Participants judged on a 10-point scale whether each excerpt was sad or happy while their electromyographical responses (zygomatic, corrugator activity) were recorded. Participants were then invited back to the laboratory, to complete a non-emotional task. This mode discrimination (minor, major) task consisted of pairs of original and inverted mode stimuli, made of shorter versions of the previously used stimuli. Participants (14; 7 amusics) had to judge whether the pairs were identical (same stimuli, same mode) or different (same stimuli different modes). In the latter task, amusics had significantly more difficulty in discriminating the mode compared to their controls. However, amusics did not differ from controls in showing normal sensitivity to mode and tempo manipulations in the emotional task. These normal behavioural judgments supported by normal psychophysiological measures indicate that emotional responses may reveal preserved or implicit pitch processing abilities in congenital amusia

    La génétique au service de la conservation d'une espÚce menacée endémique à Madagascar : la tortue radiée Astrochelys radiata

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    ThÚse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal

    Mapping Abstract Visual Feedback to a Dimensional Model of Emotion

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    Recent HCI research has looked at conveying emotions through non-visual modalities, such as vibrotactile and thermal feedback. However, emotion is primarily conveyed through visual signals, and so this research aims to support the design of emotional visual feedback. We adapt and extend the design of the "pulsing amoeba" [29], and measure the emotion conveyed through the abstract visual designs. It is a first step towards more holistic multimodal affective feedback combining visual, auditory and tactile stimuli. An online survey garnered valence and arousal ratings of 32 stimuli that varied in colour, contour, pulse size and pulse speed. The results support previous research but also provide new findings and highlight the effects of each individual visual parameter on perceived emotion. We present a mapping of all stimulus combinations onto the common two-dimensional valence-arousal model of emotion

    Compromised cerebrovascular regulation and cerebral oxygenation in pulmonary arterial hypertension

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    Background : Functional cerebrovascular regulatory mechanisms are important for maintaining constant cerebral blood flow and oxygen supply in heathy individuals and are altered in heart failure. We aim to examine whether pulmonary arterial hypertension (PAH) is associated with abnormal cerebrovascular regulation and lower cerebral oxygenation and their physiological and clinical consequences. Methods and Results : Resting mean flow velocity in the middle cerebral artery mean flow velocity in the middle cerebral artery (MCAvmean); transcranial Doppler), cerebral pressure‐flow relationship (assessed at rest and during squat‐stand maneuvers; analyzed using transfer function analysis), cerebrovascular reactivity to CO2, and central chemoreflex were assessed in 11 patients with PAH and 11 matched healthy controls. Both groups also completed an incremental ramp exercise protocol until exhaustion, during which MCAvmean, mean arterial pressure, cardiac output (photoplethysmography), end‐tidal partial pressure of CO2, and cerebral oxygenation (near‐infrared spectroscopy) were measured. Patients were characterized by a significant decrease in resting MCAvmean (P<0.01) and higher transfer function gain at rest and during squat‐stand maneuvers (both P<0.05). Cerebrovascular reactivity to CO2 was reduced (P=0.03), whereas central chemoreceptor sensitivity was increased in PAH (P<0.01), the latter correlating with increased resting ventilation (R2=0.47; P<0.05) and the exercise ventilation/CO2 production slope (Embedded Image slope; R2=0.62; P<0.05) during exercise for patients. Exercise‐induced increases in MCAvmean were limited in PAH (P<0.05). Reduced MCAvmean contributed to impaired cerebral oxygen delivery and oxygenation (both P<0.05), the latter correlating with exercise capacity in patients with PAH (R2=0.52; P=0.01). Conclusions : These findings provide comprehensive evidence for physiologically and clinically relevant impairments in cerebral hemodynamic regulation and oxygenation in PAH

    Developmental Perceptual Impairments: Cases When Tone-Deafness and Prosopagnosia Co-occur

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    Studies have shown subtle gray and white matter abnormalities in subjects with several developmental disorders including prosopagnosia, tone-deafness, and dyslexia. Correlational evidence suggests that tone-deafness and dyslexia tend to co-occur, suggesting a link between these two developmental disorders. However, it is not known whether tone-deafness can also be associated with other developmental disorders such as impaired face recognition or prosopagnosia. We addressed this question by assessing face perception abilities in a group of tone-deaf individuals and matched non-tone-deaf subjects. The Cambridge (CFMT) and the Warrington (WRMT) face memory tests were used to assess face processing in the combined group of 12, out of which six tested in the tone-deaf range. Only tone-deaf participants (two out of six) scored in the impaired range on the CFMT, one of whom was also impaired on the WRMT face memory test. Furthermore, the melodic composite score of all participants on the Montreal Battery of Evaluation of Amusia significantly correlated with their face recognition score on the CFMT. Our results suggest that in some cases tone-deafness might co-occur with face recognition impairments. It is implausible that both deficits are linked to a single cognitive dysfunction that spans different perceptual systems in different modalities. They are likely associated with a common pathogenetic mechanism of early development that leads to anomalies affecting the function of different brain systems or the connection between regions

    Personalized Risk Assessment for Prevention and Early Detection of Breast Cancer: Integration and Implementation (PERSPECTIVE I&I).

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    Early detection of breast cancer through screening reduces breast cancer mortality. The benefits of screening must also be considered within the context of potential harms (e.g., false positives, overdiagnosis). Furthermore, while breast cancer risk is highly variable within the population, most screening programs use age to determine eligibility. A risk-based approach is expected to improve the benefit-harm ratio of breast cancer screening programs. The PERSPECTIVE I&I (Personalized Risk Assessment for Prevention and Early Detection of Breast Cancer: Integration and Implementation) project seeks to improve personalized risk assessment to allow for a cost-effective, population-based approach to risk-based screening and determine best practices for implementation in Canada. This commentary describes the four inter-related activities that comprise the PERSPECTIVE I&I project. 1: Identification and validation of novel moderate to high-risk susceptibility genes. 2: Improvement, validation, and adaptation of a risk prediction web-tool for the Canadian context. 3: Development and piloting of a socio-ethical framework to support implementation of risk-based breast cancer screening. 4: Economic analysis to optimize the implementation of risk-based screening. Risk-based screening and prevention is expected to benefit all women, empowering them to work with their healthcare provider to make informed decisions about screening and prevention

    A value-based comparison of the management of ambulatory respiratory diseases in walk-in clinics, primary care practices, and emergency departments : protocol for a multicenter prospective cohort study

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    Background: In Canada, 30%-60% of patients presenting to emergency departments are ambulatory. This category has been labeled as a source of emergency department overuse. Acting on the presumption that primary care practices and walk-in clinics offer equivalent care at a lower cost, governments have invested massively in improving access to these alternative settings in the hope that patients would present there instead when possible, thereby reducing the load on emergency departments. Data in support of this approach remain scarce and equivocal. Objective: The aim of this study is to compare the value of care received in emergency departments, walk-in clinics, and primary care practices by ambulatory patients with upper respiratory tract infection, sinusitis, otitis media, tonsillitis, pharyngitis, bronchitis, influenza-like illness, pneumonia, acute asthma, or acute exacerbation of chronic obstructive pulmonary disease. Methods: A multicenter prospective cohort study will be performed in Ontario and Québec. In phase 1, a time-driven activity-based costing method will be applied at each of the 15 study sites. This method uses time as a cost driver to allocate direct costs (eg, medication), consumable expenditures (eg, needles), overhead costs (eg, building maintenance), and physician charges to patient care. Thus, the cost of a care episode will be proportional to the time spent receiving the care. At the end of this phase, a list of care process costs will be generated and used to calculate the cost of each consultation during phase 2, in which a prospective cohort of patients will be monitored to compare the care received in each setting. Patients aged 18 years and older, ambulatory throughout the care episode, and discharged to home with one of the aforementioned targeted diagnoses will be considered. The estimated sample size is 1485 patients. The 3 types of care settings will be compared on the basis of primary outcomes in terms of the proportion of return visits to any site 3 and 7 days after the initial visit and the mean cost of care. The secondary outcomes measured will include scores on patient-reported outcome and experience measures and mean costs borne wholly by patients. We will use multilevel generalized linear models to compare the care settings and an overlap weights approach to adjust for confounding factors related to age, sex, gender, ethnicity, comorbidities, registration with a family physician, socioeconomic status, and severity of illness. Results: Phase 1 will begin in 2021 and phase 2, in 2023. The results will be available in 2025. Conclusions: The end point of our program will be for deciders, patients, and care providers to be able to determine the most appropriate care setting for the management of ambulatory emergency respiratory conditions, based on the quality and cost of care associated with each alternative
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