Simulation of stochastic blockchain models

International audienceThis paper build the foundations of a simulation tool for blockchain-based applications. It takes advantage of the huge expressiveness and extensibility of PyCATSHOO framework to deal with the important variability of blockchain implementations and properties of interest. A simple stochastic model of generic blockchain-style distributed consensus system and associated performance indicators are proposed (performance in terms of consistency and ability to discard double-spending attacks). Monte Carlo simulations are applied to assess the indicators and determine their sensitivity to the variation of input parameters

Études du pouvoir discriminant des variables utilisées dans l'évaluation clinique de différents types de céphalées

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

L'évaluation du raisonnement clinique en physiothérapie

Dans le contexte de l’enseignement universitaire en sciences de la santé, des changements importants se sont produits au cours des dernières décennies dans les programmes de formation professionnelle. Un de ces changements importants est le fait que ces programmes de formation professionnelle adoptent maintenant, pour la plupart, une approche par compétence. Parallèlement à ce changement de paradigme dans la formation, les professions de la santé considèrent de plus en plus le raisonnement clinique comme étant central à la compétence du clinicien et lui réservent une place plus importante dans la formation. Ces deux changements dans la formation en science de la santé ont entrainé des questionnements quant aux méthodes d’évaluations du raisonnement clinique dans un contexte d’approche par compétence. Une des réponses à ces questionnements a été l’émergence de tests permettant de poser un jugement sur le raisonnement clinique dans le domaine de la médecine. En effet, au cours des 20 dernières années, des outils tels que le test de concordance de script (TCS) et les problèmes de raisonnement clinique (PRC) ont été développés et ont fait l’objet de plusieurs études dans les différentes spécialités de la médecine principalement. Bien que la physiothérapie partage plusieurs caractéristiques avec le domaine de la médecine, elle possède aussi plusieurs différences. En ce sens, il était pertinent de se questionner sur l’applicabilité de ces outils dans le contexte spécifique de la physiothérapie. Afin de collecter des données, des versions de ces tests ont été développées selon une table de spécification d’un cours du programme de physiothérapie de l’Université de Sherbrooke et ont été administrées à 93 étudiants volontaires des cohortes de deuxième, troisième et quatrième année du programme. Selon la procédure d’attribution des scores de ces tests, un panel d’experts (n=19) dans le domaine a aussi répondu aux items. Les résultats obtenus nous indiquent que les scores du TCS permettent de discerner des différences significatives entre les étudiants novices (2e année) et les étudiants finissants de 4e année du programme de physiothérapie, et ce, avec une taille d’effet importante (Cohen d =0,85). Par contre, il n’existe pas de différence significative entre le score moyen de la cohorte de 3e année et celui des deux autres cohortes à ce test. Des différences significatives ont été notées entre les scores du panel d’experts et celui des trois cohortes d’étudiants. Du côté des résultats aux PRC, les scores à ce test ne nous permettent pas de distinguer le niveau de développement de raisonnement clinique des étudiants en physiothérapie entre les différentes années de formation. Par contre, tout comme avec le TCS, des différences significatives ont été notées entre les scores du panel d’experts et celui des trois cohortes d’étudiants. De plus, nous avons analysé et catégorisé les 183 formulaires de stage des étudiants ayant participé à l’étude. Ces formulaires ont été catégorisés selon les observations au niveau du raisonnement clinique effectuées par les superviseurs de stage. Les résultats de cette partie de l’étude nous suggèrent que les scores des PRC sont discriminants en fonction des résultats de stage pour les différentes catégories de résultats. Du côté des scores au TCS, les étudiants ayant eu des difficultés de raisonnement clinique en stage se démarquent aussi par des scores plus faibles au TCS. Conséquemment, il est possible que ces outils puissent également permettre de dépister des étudiants ayant des difficultés de raisonnement clinique et pouvant bénéficier d’une remédiation à ce niveau. Par contre, en tenant compte de ces résultats encourageants, mais aussi du peu d’étudiants ayant eu des difficultés de raisonnement clinique en stage dans cette recherche, il sera nécessaire de confirmer ce rôle de dépistage possible avec une étude de plus grande envergure.Major changes have occurred in the last few decades in teaching the health sciences at the university level in professional training programs. One of these major changes is that most professional training programs have now adopted a competency-based approach. At the same time that this change in training paradigm was occurring, health professions were increasingly considering clinical reasoning as being at the core of clinician competency and were granting it increasing importance in their programs. These two changes in health-science training put into question the methods for assessing clinical reasoning in a competency-based approach. One of the responses to this questioning was the emergence of tests to assess clinical reasoning in the field of medicine. Indeed, over the last 20 years, instruments such as the script concordance test (SCT) and clinical reasoning problems (CRPs) were developed and have been studied primarily in the various medical specialties. While physiotherapy and medicine share a number of characteristics, they also have several differences. As a result, the appropriateness of using these tools in the specific context of physiotherapy is an issue that should be explored. In an attempt to gather data, versions of these tests were developed using a table of specifications for a course in the physiotherapy program at the Université de Sherbrooke and were administered to 93 volunteer students from the second, third, and fourth year of the program. In accordance with the scoring procedure for these tests, a panel of experts in the field (n = 19) also responded to the items. The results obtained indicate that the SCT revealed significant differences between novice students (second year) and graduating students (fourth year) in the physiotherapy program with a significant effect size (Cohen d = 0.85). In contrast, there were no significant differences between the average score for third-year students and the other two cohorts. Significant differences were noted between the scores of the panel of experts and those of the students from the three cohorts. With respect to CRPs, the scores do not allow us to distinguish the level of clinical-reasoning development of physiotherapy students in the three years of training studied. On the other hand, as with the SCT, there were significant differences between the scores of the panel of experts and those of the students from the three cohorts. Moreover, we analyzed and categorized the 183 rotation forms of the students who participated in the study. These forms were categorized according to level of clinical reasoning based on the observations of rotation supervisors. The results of this part of the study suggest that the CRP scores were discriminating in terms of rotation results for the various categories of results. As for the SCT, the students who encountered difficulties with clinical reasoning during rotations also had the lowest SCT scores. Consequently, these tools may also be able to screen for students who have problems with clinical reasoning and could benefit from remedial assistance at this level. On the other hand, while these results are encouraging, the population sample of students with clinical-reasoning difficulties during rotations in this research was small. Therefore, the role of any possible screening requires confirmation through a broader study

Building Space Time Block Codes with set partitioning for three transmit antennas: application to STTC Codes

Publication in the conference proceedings of EUSIPCO, Florence, Italy, 200

Computation of Low Mach Inviscid Compressible Flows around a Prolate Spheroid

The numerical simulation of low Mach compressible flows around a prolate spheroid is investigated using a Godunov-like numerical method. The hyperbolic differential problem -the three-dimensional Euler equations- is solved on unstructured meshes by a finite volume scheme based on Roe's upwind scheme and Turkel's low Mach preconditioner. The effects of artificial viscosity and preconditioning on the computation of Drag and Lift coefficients are investigated. The classical Roe's scheme and its low Mach preconditioned variant are both considered using a sequence of three meshes of different fineness for solutions comparison and convergence. The numerical results show the preponderant part played by the low Mach preconditioner in terms of accuracy and robustness when very subsonic flows are considered, and the importance of using a small amount of numerical dissipation

The MaggLite Post-WIMP Toolkit: Draw It, Connect It and Run It

International audienceThis article presents MaggLite, a toolkit and sketch-based interface builder allowing fast and interactive design of post-WIMP user interfaces. MaggLite improves design of advanced UIs thanks to its novel mixed-graph architecture that dynamically combines scene-graphs with interaction- graphs. Scene-graphs provide mechanisms to describe and produce rich graphical effects, whereas interaction-graphs allow expressive and fine-grained description of advanced interaction techniques and behaviors such as multiple pointers management, toolglasses, bimanual interaction, gesture, and speech recognition. Both graphs can be built interactively by sketching the UI and specifying the interaction using a dataflow visual language. Communication between the two graphs is managed at runtime by components we call Interaction Access Points. While developers can extend the toolkit by refining built-in generic mechanisms, UI designers can quickly and interactively design, prototype and test advanced user interfaces by applying the MaggLite principle: "draw it, connect it and run it"

Accompagnement virtuel personnalisé: motivation et réussite scolaire

Titre de l'écran-titre (visionné le 21 juin 2007)Également disponible en format papierMédiagraphi

Accompagnement virtuel personnalisé motivation et réussite scolaire : rapport de recherche PREP /

Titre de l'écran-titre (visionné le 21 juin 2007)Également disponible en format papierMédiagraphi

Parallelized Integrated Time-Correlated Photon Counting System for High Photon Counting Rate Applications

Time-correlated single-photon counting (TCSPC) applications usually deal with a high counting rate, which leads to a decrease in the system efficiency. This problem is further complicated due to the random nature of photon arrivals making it harder to avoid counting loss as the system is busy dealing with previous arrivals. In order to increase the rate of detected photons and improve the signal quality, many parallelized structures and imaging arrays have been reported, but this trend leads to an increased data bottleneck requiring complex readout circuitry and the use of very high output frequencies. In this paper, we present simple solutions that allow the improvement of signal-to-noise ratio (SNR) as well as the mitigation of counting loss through a parallelized TCSPC architecture and the use of an embedded memory block. These solutions are presented, and their impact is demonstrated by means of behavioral and mathematical modeling potentially allowing a maximum signal-to-noise ratio improvement of 20 dB and a system efficiency as high as 90% without the need for extremely high readout frequencies

Evaluation of the efficacy of prolonged administration of azithromycin in a murine model of chronic toxoplasmosis

The efficacy of prolonged administration of azithromycin was evaluated in a murine model of lethal chronic toxoplasmosis. Mice were challenged intraperitoneally with cysts of a moderately virulent strain of Toxoplasma gondii, observed for 4 weeks and then allocated to the treatment or control group. All 26 animals given azithromycin 100 mg/kg/day for 100 days were protected compared with 19 of 25 control animals which died (P < 0.001). Nineteen of the 20 mice in the treatment group survived for an additional month while receiving the same azithriomycin regiment but viable cysts were indentified in the brain tissue of these animals when they were killed. Although there was no significant difference between the groups in terms of the number of cysts in the brain, the administration of azithromycin was associated with a reduction in brain inflammation. The concentrations of azithromycin in the brains of five animals ranged from 0.7 to 2.3 μ/g; there was no evidence of accumulation even after 100 doses. Azithromycin merits further evaluation as primary or secondary prophylaxis against toxoplasma encephalitis in individuals at risk of developing this complicatio