Université de Montréal

About: Université de Montréal is a education organization based out in Montreal, Quebec, Canada. It is known for research contribution in the topics: Population & Context (language use). The organization has 45641 authors who have published 100476 publications receiving 4004007 citations. The organization is also known as: University of Montreal & UdeM.

A connection between score matching and denoising autoencoders

Abstract: Denoising autoencoders have been previously shown to be competitive alternatives to restricted Boltzmann machines for unsupervised pretraining of each layer of a deep architecture. We show that a simple denoising autoencoder training criterion is equivalent to matching the score (with respect to the data) of a specific energy-based model to that of a nonparametric Parzen density estimator of the data. This yields several useful insights. It defines a proper probabilistic model for the denoising autoencoder technique, which makes it in principle possible to sample from them or rank examples by their energy. It suggests a different way to apply score matching that is related to learning to denoise and does not require computing second derivatives. It justifies the use of tied weights between the encoder and decoder and suggests ways to extend the success of denoising autoencoders to a larger family of energy-based models.

The Dynamics of Collective Leadership and Strategic Change in Pluralistic Organizations

Abstract: In this article, we draw on five case studies in health care organizations to develop a process theory of strategic change in pluralistic settings characterized by diffuse power and divergent objectives. The creation of a collective leadership group in which members play complementary roles appears critical in achieving change. However. collective leadership is fragile. We identify three levels of “coupling” between leaders. organization, and environment that need to be mobilized to permit change. Since it is difficult to maintain coupling at all levels simultaneously, change tends to proceed sporadically, driven by the effects of leaders' actions on their political positions.

Two-year outcomes of surgical treatment of severe ischemic mitral regurgitation

Abstract: BackgroundIn a trial comparing coronary-artery bypass grafting (CABG) alone with CABG plus mitral-valve repair in patients with moderate ischemic mitral regurgitation, we found no significant difference in the left ventricular end-systolic volume index (LVESVI) or survival after 1 year. Concomitant mitral-valve repair was associated with a reduced prevalence of moderate or severe mitral regurgitation, but patients had more adverse events. We now report 2-year outcomes. MethodsWe randomly assigned 301 patients to undergo either CABG alone or the combined procedure. Patients were followed for 2 years for clinical and echocardiographic outcomes. ResultsAt 2 years, the mean (±SD) LVESVI was 41.2±20.0 ml per square meter of body-surface area in the CABG-alone group and 43.2±20.6 ml per square meter in the combined-procedure group (mean improvement over baseline, −14.1 ml per square meter and −14.6 ml per square meter, respectively). The rate of death was 10.6% in the CABG-alone group and 10.0% in the combined-...