Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Engineering problems frequently require solving a sequence of dual linear systems. This paper introduces recycling BiCG, that recycles the Krylov subspace from one pair of linear systems to the next pair. Augmented bi-Lanczos algorithm and modified two-term recurrence are developed for using the recycle space. Recycle space is built from the approximate invariant subspace corresponding to eigenvalues close to the origin. Recycling approach is extended to the CGS and the BiCGSTAB algorithms. Experiments on a convection-diffusion problem give promising results. / Master of Science

Yes / The isotactic polypropylene (iPP) usually shows a unique parent-daughter lamellae structure in which the parent and daughter lamellae are against each other with a near perpendicular angle (80° or 100°). Inducing a high fraction of oriented cross-hatched structure in iPP during processing is desirable for designing the bi-oriented iPP products. We processed a commercial iPP via tensile-stretching and die-drawing to evaluate the structural evolution of oriented parent-daughter lamellae. It turned out that the die-drawing process had an advantage in attaining a high fraction of oriented cross-hatched structure of iPP, as compared to the free tensile stretching. Besides, the presence of α-nucleating agents affected the formation of oriented parent-daughter lamellae in the die-drawn samples whereas such influence diminished in the free stretched ones. It was found that the confined deformation inside the die led to the well-preserved oriented cross-hatched structure in the die-drawn iPP. / This work was financially supported by the National Natural Science Foundation of China (Nos. 21704102, U1832186, and 51525305), Newton Advanced Fellowship of the Royal Society, United Kingdom (No. NA150222) and ExxonMobil Asia Pacific Research & Development Co., Ltd.

API, Application Program Interface, enables users to interact with data. However, access to an API often depends on programming proficiency, which can limit its usage. This study explored ways to improve API usage by developing and implementing a custom portal for Power BI’s API, called AdminPortal (AdP).         To address the first research question, which investigated whether AdP improved API usage compared to the existing portal, a System Usability Scale (SUS) survey was conducted. The second research question was studied through qualitative methods, including open-ended questions and documentation of use cases, to gain deeper insights into how AdP could be utilized and how it improved the workflow for Power BI administration. The results showed a statistically significant difference between AdP and the existing portal, with AdP receiving higher SUS scores. Additionally, comparing workflows with and without AdP highlighted two use cases, where AdP simplified tasks by providing a user-friendly interface, in contrast to the manual processes or coding requirements of the existing portal.   AdP demonstrated the feasibility of accessing API benefits without coding. While offering advantages like automation and flexibility, AdP also presented challenges such as information selection and user interface complexity. / API, Application Program Interface, gör det möjligt för användare att interagera med data. Tillgängligheten till API är ofta beroende av programmeringskunskaper. Detta medför begränsningar i användandet av API. Denna studie har genom att utveckla och implementera en anpassad portal för Power BI:s API, kallad AdminPortal (AdP), studerat möjligheten till en förbättring av användningen av API.  I studien användes en kombination av kvantitativa och kvalitativa metoder. Den första forskningsfrågan fokuserar på om AdP förbättrade användningen av API jämfört med att använda den befintliga Power BI-portal, vilket undersöktes med hjälp av System Usability Scale (SUS). Den andra forskningsfrågan studerar djupare insikter i hur AdP kan användas för att förbättra arbetsflödet för administration av Power BI. För detta användes kvalitativa metoder, inklusive öppna frågor under SUS-undersökningen och dokumentation av användarfall.  Resultaten visar en statistiskt signifikant skillnad mellan AdP och den befintliga portal som tillhandhålls av Power BI, där AdP får högre SUS-poäng. Dessutom, jämfördes två användarfall, med eller utan AdP, där AdP visar på mer användarvänlighet jämfört med de manuella processerna eller kodningskompetensen som krävs för den befintliga Power BI-portalen.  AdP visar möjligheten att få tillgång till fördelar av API utan kodning. Samtidigt som AdP erbjuder fördelar som automatisering och flexibilitet, har även AdP utmaningar relaterade till informationsurval och användargränssnittets komplexitet.

High-temperature superconductors belong to the group of strongly correlated materials. In these compounds, complex repulsive electron interactions and a large number of degrees of freedom lead to a rich variety of states of matter. Exotic phases like the pseudogap, charge-, spin- and pair-density waves, but also the remarkable phenomenon of superconductivity emerge, depending on doping level and temperature. However, up to now it is unclear what exactly causes these states, to what extent they are coexisting or competing, and where their borders in the phase diagram lie. A better understanding could help in finding the mechanism behind high-temperature superconductivity, but would also provide a better insight into the puzzling behavior of strongly correlated materials. This thesis tries to resolve some of these questions with focus on the underdoped pseudogap regime. Mesa structures of bismuth-based cuprate superconductors were studied using intrinsic tunneling, which allows spectroscopic characterizations of electronic density of states inside the material. A micro/nano fabrication method was developed to further reduce mesa areas into the sub square-micrometer range, in order to minimize the effect of crystal defects and measurement artifacts caused by heating induced by the measurement current. The comparison of energy scales in Bi-2201 and Bi-2212 cuprates shows that the pseudogap phenomenon is not connected to superconductivity, but possibly represents a competing spin-singlet order that is universal to all cuprates. The analysis of the upper critical field in Bi-2201 reveals a low anisotropy, which gives evidence of paramagnetically limited superconductivity. Furthermore, a new electrical doping method is demonstrated, which enables the reversible tuning the doping level of Bi-2212 and study a broad doping range upon a single sample. Using this method, two distinct critical points were observed under the superconducting dome in the phase diagram: one at the overdoped side, associated with the onset of the pseudogap and a metal to insulator transition, and one at optimal doping, associated with an enhanced "dressed" electron energy. Finally, a novel angular-dependent magnetotunneling technique is introduced, which allows for the separation of the superconducting and non-superconducting contributions to the pseudogap phenomenon. The method reveals that after an abrupt decay of the energy gap for T→Tc, weak superconducting correlations persist up to several tens of degrees above Tc.

The diploma thesis Business Intelligence in Supply Chain Management deals on the edge of IT and logistics with designing conceptual solution for BI in SCM. It covers specific needs of Supply-Chains, usage of BI in logistics, analyses the connection to the SCOR model developed by Supply-Chain Council, and designs & describes basic dimensions and relationships in the dimensional model. The primary goal is to create a general BI model solution that respects the specifics of various types of Supply-Chains in order to serve as a theoretical framework. The resulting model links to existing models designed for the Supply-Chain Management such as SCOR, Balanced Scorecard etc. To fulfil the primary goal first it is necessary to identify the specifics of various types of supply-chains, define BI use case and requirements in logistics; and by incorporating these parameters and SCOR model the BI model solution will emerge. The biggest contribution is the fulfilment of the primary goal - the creation of BI solution reference model for Supply-Chain with specific needs according to suppliers, manufacturers, distributors and retailers. With the help of this model it should be easier to coordinate, clarify goals, activities and relationships of methods used in the pre-analytical stage and implementation of the BI technologies in the Supply-Chains.

Le traitement de la douleur après chirurgie cardiaque avec sternotomie reste à ce jour un défi pour le clinicien. Chez ces patients à risque, une prise en charge non adaptée de la douleur peut altérer la réhabilitation postopératoire et majorer les complications métaboliques, immunologiques, cardiovasculaires, respiratoires, ou psychiques de la chirurgie. L’objectif de ce travail de recherche clinique en chirurgie cardiaque était : 1) d’évaluer les effets analgésiques d’une anesthésie locorégionale continue par un bloc bi-latéro-sternal (bloc BLS) par perfusion continue de ropivacaïne,2) d’évaluer l’effet du bloc BLS sur la durée de séjour en réanimation et morbidité postopératoire, chez les patients présentant un risque respiratoire accru, 3) d’évaluer l’effet analgésique d’un antiinflammatoire non stéroïdien (AINS) de référence, le kétoprofène, à une posologie conventionnelle et des posologies réduites. Les deux techniques étaient appliquées pendant les 48 heures suivant la chirurgie cardiaque.Testé (contre placebo) sur une population standard, le bloc BLS continu diminue de 41% la douleur à la mobilisation (dynamique), diminue la douleur au repos et la consommation de morphine (d’environ 40%). Il permet une reprise plus précoce de l’alimentation et du traitement per os, une mobilisation plus précoce et une plus grande satisfaction des patients. En revanche, il ne permet pas une amélioration des paramètres respiratoires (spirométrie et gaz du sang artériel). Testé (contre une prise en charge standard) sur une population à risque respiratoire accru, contrairement aux attentes, il ne réduit pas la durée de séjour en réanimation et à l’hôpital, mais il a des effets bénéfiques sur la douleur dynamique, la satisfaction des patients, l’incidence de nausées/vomissements et de troubles neurologiques de type confusionnel. Un bénéfice en termes médico-économique est suggéré par une analyse secondaire. Testé (contre placebo) sur une population à faible risque, l’utilisation du kétoprofène en plein dose permet de réduire la douleur dynamique et au repos, sans augmentation des effets indésirables rénaux et hémorragiques, habituellement craints avec les AINS. Bien que les arguments manquent pour pouvoir utiliser des posologies réduites, le kétoprofène peut néanmoins être conseillé chez ce type de patients, alors qu’il est à ce jour insuffisamment prescrit. L’étude de protocoles d’administration utilisant des posologies réduites potentialisées par une dose de charge est suggérée. / The treatment of pain after cardiac surgery with sternotomy remains to this day a challenge for the clinician. In these frail patients, non-appropriated pain treatment can alter the postoperative rehabilitation and increase metabolic, immunologic, cardiovascular, respiratory, and psychological postoperative complications. The goal of this clinical research was to evaluate:- the analgesic effects of bi-latero-sternal (BLS) block by a continuous infusion of ropivacaine, - the effect of the BLS block on the length of stay in intensive care and postoperative morbidity in patients with increased respiratory risk,- evaluate the analgesic effect of ketoprofen, the standard non-steroidal anti-inflammatory drug (NSAID), at a conventional and reduced dosages.The two techniques were applied during the 48 hours following cardiac surgery.Tested (against placebo) on a standard population, the BLS continuous block decreased pain at mobilisation (dynamic pain) by 41%, decreased pain at rest, and morphine consumption (by 40%). It allowed an earlier postoperative first dietary and oral medication intake, earlier mobilisation and a greater patients’ satisfaction. On the other hand, it did not show any significant improvement of respiratory parameters (spirometry and arterial blood gases).Tested against a standard treatment in patients with increased respiratory risk, the BLS block did not reduce the length of stay in intensive care and in hospital, but it had beneficial effects on dynamic pain, patients’ satisfaction, the incidence of nausea/vomiting and of postoperative delirium. A benefit in economics terms is suggested by a secondary analysis.Tested against placebo in a low-risk population, the use of ketoprofen in full dose regimen, reduced pain at mobilisation and at rest, without increasing renal adverse effects or bleeding (as it could be feared with NSAIDs). We missed to demonstrate the ketoprofen efficacy at reduced doses. Ketoprofen may be recommended on a low-risk population, while it is insufficiently prescribed so far. The study of protocols using a reduced dosage potentiated by a loading dose is suggested.

Este trabalho apresenta um método computacional que classifica as mamografias no padrão de densidade BI-RADS, visando auxiliar a detecção precoce do câncer de mama, seja essa realizada por análise visual ou por auxílio computadorizado. A classificação das mamografias em bancos padronizados objetiva eliminar conflitos entre laudos mamográficos de diferentes profissionais, bem como quanto à conduta médica a ser seguida. Entretanto, o estabelecimento de bancos feito visualmente e principalmente em períodos diferentes dificulta sua uniformização, proporcionando uma classificação muito subjetiva e relativamente grosseira em conseqüência a grande variação entre e inter observadores. O método desenvolvido permitiu classificar as imagens independentemente da subjetividade própria à observação visual de quem organizou o banco ou da técnica de exposição aos raios X utilizada. Os resultados foram superiores a 92% mesmo para bancos de imagens totalmente diferentes. Esses resultados foram obtidos respeitando-se as possíveis diferenças de interpretações de diversas equipes médicas. Além do estabelecimento de banco de mamografias com limiares entre as composições bem quantificadas, com esta ferramenta, tanto os estagiários poderão ser treinados para classificar as imagens no padrão de densidades do BI-RADS, respeitando as particularidades locais, quanto os resultados dos CAD poderão ser comparados. / This thesis presents a computational method that classifies the mammography into the composition of the breast tissue density patterns described in the BI-RADS protocol, intended to help in the early detection of breast cancer, either if this detection happens to be realized by visual analysis or by computerized support. The classification of the mammography in standardized database intends to eliminate issues between mammography awards of distinct professionals and the correct medical conduct to be followed. However, the determination of database only visually, especially in different periods, difficult it\'s to standardize, causing an extremely subjective classification and relatively superficial in consequence of the large inter-and intraobserver variability. The method allows classifying the images independently of the subjective quality of the visual analysis from who organized the database or from the technique of the exposition to X-ray employed. The results were superior of 92% even to database totally distinct. These results were obtained respecting eventual differences of interpretation from several medical groups. Beside the establishment of mammography database with thresholding between the well quantified categories, this methodology will consent to probationers to be trained for classify the images according to the composition of the breast tissue density patterns described in the BI-RADS, respecting its local particularity. Likewise, with this methodology, the results from CAD would be compared.

Les machines électriques à aimants, appréciées pour leurs densités énergétiques volumique et massique, équipent la majorité des véhicules électrifiés. Par contre, dans la zone à puissance constante d’un système de propulsion, les commander à pertes maîtrisées, cela en démagnétisant les aimants mais de façon réversible, reste une gageure, particulièrement sous environnement thermique changeant. Les solutions simples pour se prémunir d’une démagnétisation irréversible sont coûteuses: surdimensionner ou ajouter une terre très très rare (Dysprosium).Cette thèse propose d’ajouter à l’approche de la démagnétisation réversible universellement utilisée, celle d’une boite de vitesse électromagnétique. Pour cela on conçoit une machine pentaphasée à aimants.Passer de trois à cinq phases permet alors d’augmenter les paramètres de réglage de l’alimentation électrique et, moyennant approximation, de disposer de deux machines fictives à p et 3p paires de pôles, chacune pouvant contribuer de façon équivalente à la production du couple. Pratiquement, l’utilisation optimale de ces deux machines permet de reconstituer la fonction de boite de vitesse. / Permanent Magnet electrical machines , appreciated for their high power density, equip the majority of the electrified vehicles. However, controlling these machines, in the constant power range of the propulsion system while mastering the losses, with PM reversible demagnetization remains a challenge especially under varying thermal environnement. Proposed solutions aim for protecting PM from irreversible demagnetization are costly: oversizing or using very rare earth PM (Dysprosium).In this thesis, we proposed to add on the reversible demagnetization approach universally used , that of a electromagnetic gearbox. Thus, we design a five phase PM machine.Increasing the phase number from three to five, increases the adjustment parameter of the electrical supply, and allows to have two fictitious machines with p and 3 p poles. Each fictitious machine contributes equivalently in producing torque. Practically, the optimal use of these two machines leads to reconstructing the gearbox function.

Cette thèse a pour objectif la mise au jour et la description des pratiques enseignantes en matière de comparaison des langues dans les écoles immersives français-occitan Calandretas. Les activités centrées sur l’observation comparée du fonctionnement de différentes langues font depuis quelques décennies l’objet de nombreuses recherches et suscitent l’intérêt des didacticiens, qui y voient de nouvelles pistes de travail pour l’enseignement des langues étrangères, de la langue maternelle et/ou de scolarisation avec, en arrière-plan, la perspective d’une meilleure maîtrise des langues et du langage. La mise en œuvre de ces activité questionne très clairement le rôle et la place attribués aux langues dans la formation linguistique des élèves, qu’il s’agisse des langues de leur biographie langagière, des langues du curricula, ou de langues inconnues. Les tendances actuelles allant dans le sens du rapprochement des langues entre elles, que ce soit à des fins d’apprentissage d’une langue-cible en particulier ou dans la perspective, plus large, d’une éducation aux langues et au langage, nous nous sommes demandée ce qu’il en était dans le contexte très spécifique de l’enseignement bilingue, et, plus particulièrement, dans le contexte de l’enseignement immersif en langue régionale. Dans les écoles occitanes Calandretas, les enseignants comparent-ils les deux langues de scolarisation (l’occitan et le français), et/ou d’autres langues entre elles ? Si oui, comment et pourquoi ? A partir d’une étude des pratiques déclarées et des pratiques observées menée auprès d’enseignants de cycle 3, notre thèse se propose de rendre compte de la façon dont sont mises en place les situations d’observation comparée du fonctionnement de l’occitan et du français et/ou d’autres langues, mais aussi d’étudier les contenus linguistiques abordés à travers la comparaison. Située à l’interface de la linguistique et de la didactique du plurilinguisme, la thèse cherche également, sur le plan épistémologique, à clarifier la place de la comparaison des langues dans les approches plurielles des langues et des cultures et à préciser ce que signifie comparer les langues. / This thesis aims at presenting and describing the teaching practices related to language comparison in the immersive French-Occitan schools “Calandretas”. Activities focusing on the comparative observation of the functioning of different languages have been widely researched for a number of decades. They are of great interest to applied linguists who consider them as new ways of approaching language teaching, as much of foreign languages, as of the mother tongue or the language of schooling. The implementation of these activities very clearly questions the role and place attributed to languages in the language training of pupils; it addresses the languages of their language biography, of the curriculum or even languages unknown to them. Current trends lean towards disciplinary decompartmentalization and the setting up of links between languages, whether for the purpose of learning a particular target language or the wider perspective of language education. Therefore, I wanted to explore what took place in the very specific context of bilingual education, more specifically in the context of immersive teaching of the regional language. Do the teachers in the Occitan Calandretas schools compare the two languages of schooling (Occitan and French), and / or other languages? If so, how and why? Based on a study of reported and observed practices of teachers of Key Stage 3, our thesis offers to report not only on the way in which the situations of comparative observation of Occitan and French and / or other languages functioning are set up, but also to study the linguistic contents covered by the comparison. Situated at the interface between linguistics and the didactics of multilingualism, this work also seeks, to clarify the place of the comparison of languages in the plural approaches of languages and cultures from the epistemological point of view and to clarify what it means to compare languages.