A Computational Interpretation of Parametricity

Reynolds' abstraction theorem has recently been extended to lambda-calculi with dependent types. In this paper, we show how this theorem can be internalized. More precisely, we describe an extension of Pure Type Systems with a special parametricity rule (with computational content), and prove fundamental properties such as Church-Rosser's and strong normalization. All instances of the abstraction theorem can be both expressed and proved in the calculus itself. Moreover, one can apply parametricity to the parametricity rule: parametricity is itself parametric

The effect of high intensity interval exercise on postprandial triacylglycerol and leukocyte activation - monitored for 48h post exercise

Peer reviewedPublisher PD

Urban Traffic Eco-driving: A Macroscopic Steady-State Analysis

International audienceThe problem of traveling at maximum energy efficiency (Eco-Driving) is addressed for urban traffic networks at macroscopic level. The scope of this paper is the analysis of the steady-state behavior of the system, given certain boundary flows conditions fixed by traffic lights timings, and in presence of a traffic control policy based on variable speed limits. The formal study is carried out on a two-cells variable length model adapted to the urban setup from previous works on highway traffic. Informative traffic metrics, aimed at assessing traffic and vehicles performance in terms of traveling time, infrastructure utilization and energy consumption, are then defined and adapted to the new macroscopic traffic model. If congestion in a road section does not spill back or vanish, the system is stable and many different equilibrium points can be reached via variable speed limits. Efficient operation points and traffic conditions are identified as a trade-off between optimization of global traffic energy consumption, traveling time and infrastructure utilization

Gas permeability in rarefied flow conditions for characterization of mineral membrane support

International audienceGas Permeability Measurement Technique (GPMT) has the advantage of being a non-destructive method, which is efficient in characterizing filtration membranes. Ceramic filtration membranes consist of successive layers of micro (support) to nano size (skin) pores. When gas flows through such a small scale structure, the molecular mean free path becomes comparable to the pore size. The Slip flow model, validated to describe the gas transport properties under rarefied flow conditions in a microchannel, is extended to porous media. The porous structure is modeled as a cluster of several identical cylindrical channels

Progressive Attenuation of the Longitudinal Kinetics in the Common Carotid Artery: Preliminary in Vivo Assessment

Longitudinal kinetics (LOKI) of the arterial wall consists of the shearing motion of the intima-media complex over the adventitia layer in the direction parallel to the blood flow during the cardiac cycle. The aim of this study was to investigate the local variability of LOKI amplitude along the length of the vessel. By use of a previously validated motion-estimation framework, 35 in vivo longitudinal B-mode ultrasound cine loops of healthy common carotid arteries were analyzed. Results indicated that LOKI amplitude is progressively attenuated along the length of the artery, as it is larger in regions located on the proximal side of the image (i.e., toward the heart) and smaller in regions located on the distal side of the image (i.e., toward the head), with an average attenuation coefficient of −2.5 ± 2.0%/mm. Reported for the first time in this study, this phenomenon is likely to be of great importance in improving understanding of atherosclerosis mechanisms, and has the potential to be a novel index of arterial stiffness

Arterial Bandwidth Maximization via Signal Offsets and Variable Speed Limits Control

International audienceThe problem of maximizing bandwidth along an arterial is here addressed by use of two combined control actions: traffic lights offsets and variable speed limits. The optimization problem has been enriched in order to account for traffic energy consumption and network travel time, thus avoiding impractical or undesirable solutions. A traffic microscopic simulator has been used to assess the performance of the proposed technique in terms of energy consumption, travel time, idling time, and number of stops. The theoretical bandwidth proves to be well correlated with idling time and number of stops, while the variable speed limits control shows interesting advantages in terms of energy consumption without penalizing the travel time. An analysis of the Pareto optimum has been carried out to help the designer choose a trade-off in the multi-objective optimization

Arterial Bandwidth Maximization via Signal Offsets and Variable Speed Limits Control

International audienceThe problem of maximizing bandwidth along an arterial is here addressed by use of two combined control actions: traffic lights offsets and variable speed limits. The optimization problem has been enriched in order to account for traffic energy consumption and network travel time, thus avoiding impractical or undesirable solutions. A traffic microscopic simulator has been used to assess the performance of the proposed technique in terms of energy consumption, travel time, idling time, and number of stops. The theoretical bandwidth proves to be well correlated with idling time and number of stops, while the variable speed limits control shows interesting advantages in terms of energy consumption without penalizing the travel time. An analysis of the Pareto optimum has been carried out to help the designer choose a trade-off in the multi-objective optimization

Speed Advisory and Signal Offsets Control for Arterial Bandwidth Maximization and Energy Consumption Reduction

International audienceThe problem of maximizing bandwidth along anarterial is addressed here by use of two combined control actions:traffic light offsets and recommended speeds. The optimizationproblem has been enriched in order to account for traffic energyconsumption and network travel time, thus avoiding impracticalor undesirable solutions. A traffic microscopic simulator has beenused to assess the performance of the proposed technique in termsof energy consumption, travel time, idling time, and number ofstops. The correlation of theoretical bandwidth with known trafficperformance metrics is studied, and an analysis of the Paretooptimum has been carried out to help the designer choose atradeoff in the multiobjective optimization. Finally, an evaluationof the traffic performance at different levels of traffic demandaims at showing the best operation conditions of the proposedstrategy. A demand-dependent optimization is proposed

Ageing of reverse osmosis membranes under gamma irradiation

Reverse osmosis (RO) shows a real growth among the water and wastewater treatment processes available (evaporation, ions exchange, electrodialysis) since forty years. RO has become the most used processes for desalination of seawater or saline water. Following Fukushima-Daiichi accident, RO has been chosen as the final treatment of the seawater used to cool the damaged nuclear reactors. Only very few studies and data has been published about RO applied to radioactive wastewater. Currently RO membranes are made of polymers that are sensitive to irradiation and could be strongly damaged due to these ionizing radiations. Data about the ageing of the membranes under these operating conditions are very difficult to obtain even if RO seems to be efficient in the process used in Fukushima. Please click Additional Files below to see the full abstract