École Polytechnique de Montréal

About: École Polytechnique de Montréal is a education organization based out in Montreal, Quebec, Canada. It is known for research contribution in the topics: Finite element method & Computer science. The organization has 8015 authors who have published 18390 publications receiving 494372 citations.

Red Lesion Detection Using Dynamic Shape Features for Diabetic Retinopathy Screening

Abstract: The development of an automatic telemedicine system for computer-aided screening and grading of diabetic retinopathy depends on reliable detection of retinal lesions in fundus images. In this paper, a novel method for automatic detection of both microaneurysms and hemorrhages in color fundus images is described and validated. The main contribution is a new set of shape features, called Dynamic Shape Features, that do not require precise segmentation of the regions to be classified. These features represent the evolution of the shape during image flooding and allow to discriminate between lesions and vessel segments. The method is validated per-lesion and per-image using six databases, four of which are publicly available. It proves to be robust with respect to variability in image resolution, quality and acquisition system. On the Retinopathy Online Challenge's database, the method achieves a FROC score of 0.420 which ranks it fourth. On the Messidor database, when detecting images with diabetic retinopathy, the proposed method achieves an area under the ROC curve of 0.899, comparable to the score of human experts, and it outperforms state-of-the-art approaches.

A kinematic theory of rapid human movements

Abstract: This paper describes how a synergy made up of a pair of agonist and antagonist systems involved in the production of a rapid movement can control movement time A quadratic law is derived to predict the movement time as a function of the various parameters describing the neuromuscular synergy Conditions for a simplified description of the process, using a power law, are also presented It is predicted that movement time can be controlled at the input level by the ratio of the agonist to antagonist commands or at the system level by modifying the total log-time delay or the log-response time of the agonist or antagonist neuromuscular networks Adapting this approach to the specific case of movements executed under different spatial accuracy demands, it is found that movement time is linked to the inverse of the relative spatial error by similar laws The whole approach is used to explain within a single framework all the observations that have been reported concerning speed/accuracy trade-offs Strategies for controlling movement amplitude and duration are analyzed, and other predictions dealing with EMG, acceleration patterns, load effects and changes in the asymmetry of the velocity profile are also discussed

An empirical study of the impact of modern code review practices on software quality

Abstract: Software code review, i.e., the practice of having other team members critique changes to a software system, is a well-established best practice in both open source and proprietary software domains. Prior work has shown that formal code inspections tend to improve the quality of delivered software. However, the formal code inspection process mandates strict review criteria (e.g., in-person meetings and reviewer checklists) to ensure a base level of review quality, while the modern, lightweight code reviewing process does not. Although recent work explores the modern code review process, little is known about the relationship between modern code review practices and long-term software quality. Hence, in this paper, we study the relationship between post-release defects (a popular proxy for long-term software quality) and: (1) code review coverage, i.e., the proportion of changes that have been code reviewed, (2) code review participation, i.e., the degree of reviewer involvement in the code review process, and (3) code reviewer expertise, i.e., the level of domain-specific expertise of the code reviewers. Through a case study of the Qt, VTK, and ITK projects, we find that code review coverage, participation, and expertise share a significant link with software quality. Hence, our results empirically confirm the intuition that poorly-reviewed code has a negative impact on software quality in large systems using modern reviewing tools.