Changement de l'efficacité énergétique pour fins de chauffage dans le secteur résidentiel au Québec, 1989-1998

L'évolution de la consommation d'énergie entre deux périodes peut être décomposée de manière à souligner les rôles joués par le niveau d'activité économique, le changement structurel à l'intérieur du secteur étudié, les conditions climatiques et l'efficacité énergétique. Nous adaptons la méthodologie appliquée par l'Office de l'efficacité énergétique du gouvernement canadien pour prendre en compte une caractéristique particulière du chauffage de l'espace du secteur résidentiel québécois, à savoir l'usage prédominant de l'électricité. De plus, nous utilisons des informations statistiques qui ont été spécifiquement recueillies par Hydro-Québec et qui permettent d'analyser le changement de la consommation d'énergie pour fins de chauffage du secteur résidentiel québécois entre 1989 et 1998. La consommation d'énergie de ce secteur a chuté de 20,8% malgré une hausse de 13,3% de l'espace à chauffer. La différence de température à elle seule explique 15,5% de la baisse de consommation alors que l'efficacité accrue des logements existants avant 1989 contribue à la réduction pour 13,3%; enfin, l'efficacité supérieure des logements construits depuis 1989 contribue pour 3,5%. La prise en compte de l'efficacité énergétique des nouveaux et des anciens logements est une dimension nouvelle dans ce type d'analyses.Indicateur, efficacité énergétique, secteur résidentiel, chauffage des locaux

Changement de l'efficacité énergétique pour fins de chauffage dans le secteur résidentiel au Québec, 1989-1998

L'évolution de la consommation d'énergie entre deux périodes peut être décomposée de manière à souligner les rôles joués par le niveau d'activité économique, le changement structurel à l'intérieur du secteur étudié, les conditions climatiques et l'efficacité énergétique. Nous adaptons la méthodologie appliquée par l'Office de l'efficacité énergétique du gouvernement canadien pour prendre en compte une caractéristique particulière du chauffage de l'espace du secteur résidentiel québécois, à savoir l'usage prédominant de l'électricité. De plus, nous utilisons des informations statistiques qui ont été spécifiquement recueillies par Hydro-Québec et qui permettent d'analyser le changement de la consommation d'énergie pour fins de chauffage du secteur résidentiel québécois entre 1989 et 1998. La consommation d'énergie de ce secteur a chuté de 20,8% malgré une hausse de 13,3% de l'espace à chauffer. La différence de température à elle seule explique 15,5% de la baisse de la consommation alors que l'efficacité accrue des logements existants avant 1989 contribue à la réduction pour 13,3%; enfin, l'efficacité supérieure des logements construits depuis 1989 contribue pour 3,5%. La prise en compte de l'efficacité énergétique des nouveaux et des anciens logements est une dimension nouvelle dans ce type d'analyses.Indicateur, efficacité énergétique, secteur résidentiel, chauffage des locaux

The geosimulation of West Nile virus propagation: a multi-agent and climate sensitive tool for risk management in public health

<p>Abstract</p> <p>Background</p> <p>Since 1999, the expansion of the West Nile virus (WNV) epizooty has led public health authorities to build and operate surveillance systems in North America. These systems are very useful to collect data, but cannot be used to forecast the probable spread of the virus in coming years. Such forecasts, if proven reliable, would permit preventive measures to be put into place at the appropriate level of expected risk and at the appropriate time. It is within this context that the Multi-Agent GeoSimulation approach has been selected to develop a system that simulates the interactions of populations of mosquitoes and birds over space and time in relation to the spread and transmission of WNV. This simulation takes place in a virtual mapping environment representing a large administrative territory (e.g. province, state) and carried out under various climate scenarios in order to simulate the effects of vector control measures such as larviciding at scales of 1/20 000 or smaller.</p> <p>Results</p> <p>After setting some hypotheses, a conceptual model and system architecture were developed to describe the population dynamics and interactions of mosquitoes (genus <it>Culex</it>) and American crows, which were chosen as the main actors in the simulation. Based on a mathematical compartment model used to simulate the population dynamics, an operational prototype was developed for the Southern part of Quebec (Canada). The system allows users to modify the parameters of the model, to select various climate and larviciding scenarios, to visualize on a digital map the progression (on a weekly or daily basis) of the infection in and around the crows' roosts and to generate graphs showing the evolution of the populations. The basic units for visualisation are municipalities.</p> <p>Conclusion</p> <p>In all likelihood this system might be used to support short term decision-making related to WNV vector control measures, including the use of larvicides, according to climatic scenarios. Once fully calibrated in several real-life contexts, this promising approach opens the door to the study and management of other zoonotic diseases such as Lyme disease.</p

Coupled study of the film and spray on a basic annular prefiming airblast atomizer

[EN] One way to increase efficiency and reduce pollution in transport and energetic domain is designing fuel injectors with better atomization. In this work, experiments were performed on a prefilming airblast atomizer often used in gas turbine engines. For this purpose, a new injector was designed to visualize the prefilming zone and the primary atomization together. The flow configuration corresponds to an annular liquid film sheared by inner high velocity airflows. High speed Shadowgraphy was used to observe film and spray, liquid film frequency, wave velocity and wave deformation, primary breakup regime. Finally, a link between liquid film and the primary atomization are shown first qualitatively and after quantitatively.Gosselin, V.; Ferret, B.; Bazile, R. (2017). Coupled study of the film and spray on a basic annular prefiming airblast atomizer. En Ilass Europe. 28th european conference on Liquid Atomization and Spray Systems. Editorial Universitat Politècnica de València. 505-512. https://doi.org/10.4995/ILASS2017.2017.4626OCS50551

The potential impact of climate change on annual and seasonal mortality for three cities in Québec, Canada

<p>Abstract</p> <p>Background</p> <p>The impact of climate change and particularly increasing temperature on mortality has been examined for three cities in the province of Québec, Canada.</p> <p>Methods</p> <p>Generalized linear Poisson regression has been fitted to the total daily mortality for each city. Smooth parametric cubic splines of temperature and humidity have been used to do nonlinear modeling of these parameters. The model, to control for day of the week and for non-temperature seasonal factors, used a smooth function of time, including delayed effects. The model was then used to assess variation in mortality for simulated future temperatures obtained from an atmospheric General Circulation Model coupled with downscaling regression techniques. Two CO₂emission scenarios are considered (scenarios A2 and B2). Projections are made for future periods around year 2020 (2010–2039), 2050 (2040–2069) and 2080 (2070–2099).</p> <p>Results</p> <p>A significant association between mortality and current temperature has been found for the three cities. Under CO₂emission scenarios A2 and B2, the mortality model predicts a significant increase in mortality in the summertime, and a smaller, but significant decrease in the fall season. The slight variations in projected mortality for future winter and spring seasons were found to be not statistically significant. The variations in projected annual mortality are dominated by an increase in mortality in the summer, which is not balanced by the decrease in mortality in the fall and winter seasons. The summer increase and the annual mortality range respectively from about 2% and 0.5% for the 2020 period, to 10% and 3% for the years around 2080. The difference between the mortality variations projected with the A2 or B2 scenarios was not statistically significant.</p> <p>Conclusion</p> <p>For the three cities, the two CO₂emission scenarios considered led to an increase in annual mortality, which contrasts with most European countries, where the projected increase in summer mortality with respect to climate change is overbalanced by the decrease in winter mortality. This highlights the importance of place in such analyses. The method proposed here to establish these estimates is general and can also be applied to small cities, where mortality rates are relatively low (ex. two deaths/day).</p

Purification and characterization of an extracellular amylase from Lactobacillus plantarum strain A6

Extracellular amylase from #Lactobacillus plantarum$ A6 was purified by fractionated precipitation with ammonium sulphate and by anion exchange chromatography. The homogeneity of the purified fraction was tested by polyacrylamide gel electrophoresis and showed multiple amylase forms. A major form had an estimated molecular weight of 50 kDa. It was identified as an alpha-amylase, with an optimum pH of 5.5, an optimum temperature of 65°C and Km value of 2.38 g l-1 with soluble starch substrate. The enzyme was inhibited by N-bromosuccinimide, iodine and acetic acid. The enzyme activation energy was 30.9 kJ mol-1. (Résumé d'auteur

One-Cycle Pruning: Pruning ConvNets Under a Tight Training Budget

Introducing sparsity in a neural network has been an efficient way to reduce its complexity while keeping its performance almost intact. Most of the time, sparsity is introduced using a three-stage pipeline: 1) train the model to convergence, 2) prune the model according to some criterion, 3) fine-tune the pruned model to recover performance. The last two steps are often performed iteratively, leading to reasonable results but also to a time-consuming and complex process. In our work, we propose to get rid of the first step of the pipeline and to combine the two other steps in a single pruning-training cycle, allowing the model to jointly learn for the optimal weights while being pruned. We do this by introducing a novel pruning schedule, named One-Cycle Pruning, which starts pruning from the beginning of the training, and until its very end. Adopting such a schedule not only leads to better performing pruned models but also drastically reduces the training budget required to prune a model. Experiments are conducted on a variety of architectures (VGG-16 and ResNet-18) and datasets (CIFAR-10, CIFAR-100 and Caltech-101), and for relatively high sparsity values (80%, 90%, 95% of weights removed). Our results show that One-Cycle Pruning consistently outperforms commonly used pruning schedules such as One-Shot Pruning, Iterative Pruning and Automated Gradual Pruning, on a fixed training budget.Comment: Accepted at Sparsity in Neural Networks (SNN 2021