Properties and Algorithms for Unfolding of Probabilistic Data-flow Graphs

It is known that any selection statement (e.g. if and switch-case statements) in an application is associated with a probability which could either be predetermined by user input or chosen at runtime. Such a statement can be regarded as a computation node whose computation time is represented by a random variable. This paper focuses on iterative applications (containing loops) reecting those uncertainties. Such an application can then be transformed to a probabilistic data-ow graph. Two timing models, the time-invariant and time-variant models, are introduced to characterize the nature of these applications. Since there can be many unfolding factors associated with each of the possible graph outcomes, for the time-invariant model, we propose a means of selecting a constant minimum rate-optimal unfolding factor for unfolding the probabilistic graph. We demonstrate that this factor guarantees the best schedule length. We also suggest a good estimate for choosing an unfolding factor for..

Properties and Algorithms for Unfolding of Probabilistic Data-flow Graphs

It is known that any selection statement (e.g. if and switch-case statements) in an application is associated with a probability which could either be predetermined by user input or chosen at runtime. Such a statement can be regarded as a computation node whose computation time is represented by a random variable. This paper focuses on iterative applications (containing loops) reecting those uncertainties. Such an application can then be transformed to a probabilistic data-ow graph. Two timing models, the time-invariant and time-variant models, are introduced to characterize the nature of these applications. Since there can be many unfolding factors associated with each of the possible graph outcomes, for the time-invariant model, we propose a means of selecting a constant minimum rate-optimal unfolding factor for unfolding the probabilistic graph. We demonstrate that this factor guarantees the best schedule length. We also suggest a good estimate for choosing an unfolding..

Do spices have the same odor on the other side of world ? effect of culture on spice odor perception

International audienceCulture is known to affect people’s ability to identify or describe everyday odors (Chrea et al, 2005). For example, Vietnamese students are better at identifying the odor of ginger than French students who are better at identifying the odor of blackcurrant. Familiarity has been suggested as a factor underlying this effect. The goal of this study was to evaluate further this interpretation and to explore its role in the perception of spices in France and Thailand. We evaluated if food habits link to a given culture (e.g. eating curry) would impact individuals’ ability to identify (verbal task) or recognize (perceptual task) odors presented alone or in mixtures. Six spices were selected from a questionnaire and an identification pre-test performed in France and Thailand. Among these spices three were more familiar to French people (cinnamon, cumin, star anise) and three to Thai people (garlic powder, curcuma and lemongrass). One hundred and twenty participants were recruited in each country. Half of them carried out the verbal task and the other half carried out the perceptual task. In the verbal task participants had to identify each spice by selecting the right spice name among six names. In the perceptual task, they had to do the same thing by selecting the right flask among six un-named spice flasks. Data were analyzed using signal detection theory. The results show a global significant effect of the familiarity level, strengthening previous literature data on the impact of familiarity on odor perception. The more people are familiar with spices, the more they are able to recognize them. But as expected, this effect is dependent on the task (verbal vs. perceptual) and participants’ country. Thai assessors performed better in the perceptual task than in the verbal task, whatever the familiarity level. No such effect was observed for French participants