Another Multidimensional Synchronous Dataflow: Simulating Array-OL in Ptolemy II

Computation intensive multidimensional applications appear in many application domains such as video processing or detection systems. We present here the Array-OL specification model to handle such multidimensional applications. This model is compared to the Multidimensional Synchronous Dataflow proposition by Lee et al. We also detail in this a new domain in the Ptolemy simulation environment dedicated to Array-OL specification simulation

Multi-layered Spiking Neural Network with Target Timestamp Threshold Adaptation and STDP

Spiking neural networks (SNNs) are good candidates to produce ultra-energy-efficient hardware. However, the performance of these models is currently behind traditional methods. Introducing multi-layered SNNs is a promising way to reduce this gap. We propose in this paper a new threshold adaptation system which uses a timestamp objective at which neurons should fire. We show that our method leads to state-of-the-art classification rates on the MNIST dataset (98.60%) and the Faces/Motorbikes dataset (99.46%) with an unsupervised SNN followed by a linear SVM. We also investigate the sparsity level of the network by testing different inhibition policies and STDP rules

Unsupervised Visual Feature Learning with Spike-timing-dependent Plasticity: How Far are we from Traditional Feature Learning Approaches?

Spiking neural networks (SNNs) equipped with latency coding and spike-timing dependent plasticity rules offer an alternative to solve the data and energy bottlenecks of standard computer vision approaches: they can learn visual features without supervision and can be implemented by ultra-low power hardware architectures. However, their performance in image classification has never been evaluated on recent image datasets. In this paper, we compare SNNs to auto-encoders on three visual recognition datasets, and extend the use of SNNs to color images. The analysis of the results helps us identify some bottlenecks of SNNs: the limits of on-center/off-center coding, especially for color images, and the ineffectiveness of current inhibition mechanisms. These issues should be addressed to build effective SNNs for image recognition

The Physicians’ Practice Assessment Questionnaire on asthma and COPD

SummaryWe describe a new tool, the Physicians’ Practice Assessment Questionnaire (PPAQ), designed for the global self-assessment of implementation of asthma and COPD guidelines, as determined by the percentage of patients in whom physicians estimate that they implement guidelines key recommendations. Some of its properties were assessed by a group of 47 general practitioners (GPs), and test–retest data were obtained in repeating the questionnaire at a 5-week interval without intervention in a sub-group of 28 practitioners. Answers to the various questions were globally reproducible. The lowest scores (recommendations implemented in less than 50% of their patients) were: 1) for both asthma and COPD: referral for patient education, provision of a written action plan and regular assessment of inhaler technique, 2) for asthma: referral to a specialist for difficult to control asthma or uncertain diagnosis, and 3) for COPD: assessment of lung function and disability according to specific criteria and referral to a rehabilitation program. The analysis showed sufficient internal consistency for both questionnaires (Cronbach alphas 0.7617 for asthma and 0.8317 for COPD). Pearson’s correlations indicated good test–retest (r = 0.6421, p = 0.0002 for asthma; r = 0.6801, p < 0.0001 for COPD). In conclusion, the PPAQ is a new tool to assess implementation of asthma and COPD guidelines; it has the potential to identify care gaps that can be specifically targeted for intervention

Prevalence of respiratory symptoms in an athlete population

AbstractThis study aimed to look at the prevalence and type of respiratory symptoms experienced by athletes and to assess the possible influence on the perception of symptoms of training duration and environment. A group of 698 athletes (107 with diagnosed or self-reported asthma) filled out a questionnaire on their respiratory condition. They exercised either in cold air (n=176), dry air (n=384), humid air (n=95) or mixed dry and humid air (n=43). Past exercise-related symptoms reported by athletes were breathlessness (48.7%), phlegm production (22.8%), wheezing (15.6%), cough (15.2%), and chest tightness (7.4%). Only 25% of asthmatic athletes reported having current exercise-induced symptoms of breathlessness, 21.7%, wheezing and 17.4%, chest tightness; current exercise-induced symptoms of breathlessness, wheezing or chest tightness were also reported, respectively, in 38.9%, 3.6% and 2.7% of athletes without a diagnosis of asthma. The perception of exercise-induced symptoms was not influenced by the duration of training or environment. In conclusion, (1) a minority of asthmatic athletes report troublesome respiratory symptoms with exercise, (2) breathlessness is not more frequently reported in asthmatic athletes than in those without such diagnosis while cough and wheezing are more common in asthmatic subjects and (3) the prevalence of respiratory symptoms is independent of training environment and duration of training