Computer-assisted Teaching in Class Situation: a High-school Math Lab on Vectors

published as a volume in Lecture Notes in Computer ScienceInternational audienceThis paper presents our design and experiment of a computerassisted class laboratory on vectors in high-school. Our main goal is to improve the acquisition on notions by all pupils, from advanced level to remedial level. Our secondary goal is to improve the motivation of pupils toward maths and sciences. Our approach consists in making the pupils practice the notions included in a given set of pedagogic objectives, and to do it through real worldinspired problems. We draw on MobiNet, a platform that simulate programmable mobiles on screen and through the network. Our class laboratory consists of a set of pre-programmed interactive simulations, allowing the pupils to react on their errors and to validate each exercise in an autonomous way. This class laboratory was conducted in the same conditions and constraints than an ordinary math lab: same duration, and no preparation of the pupils (but the ordinary math course). Still, the autonomy of the exercises and the network ability would also allow the use with no teacher on place. In this paper, we describe our vector class laboratory experiment: objectives, design, conduction, and evaluation

Preuves, types et sous-types

This thesis is about the theoretical and practical study of a type system applied to functionnal programming certification. The base system is system ST invented by C.Raffalli; this system embeds polymorphism, subtyping and omission of non-algorithmic content. We firstly study models of this theory defined by the type system, building an axiomatic basis based on lattices that allows to express both calculus and logic. On this base, we study the type system itself, prove subject reduction, and the possibility of defining inside the system normalisability and reducibility properties. In the continuation, more applied, we study encoding of rich datatypes inspired from functionnal languages -including first-order modules- into Lambda-Calculus, and show that they behave well in the system through an embedding. The methodology of this part allows to extend the language preserving a consistency criterion ensuring the safety of the typed code.Cette thèse porte sur l'étude théorique et pratique d'un système de typage appliqué à la preuve de programmes de style fonctionnels. Le système de base est le système ST créé par C.Raffalli; il comporte, outre le polymorphisme, du sous-typage et de l'omission de contenu non-algorithmique. Nous étudions tout d'abord les modèles de la théorie définie par le système de types, en construisant une axiomatique basée sur les treillis permettant de modéliser le calcul et la logique. Nous étudions sur cette base le système de types, montrons la réduction du sujet, et la possibilité de définir en interne la normalisabilité et la réductibilité des programmes. Dans la suite de la thèse, plus appliquée, nous étudions des codages de types de données riches inspirés des langages fonctionnels - y incluant notamment un système de modules du premier ordre- dans le Lambda-Calcul, et montrons qu'ils s'intègrent harmonieusement dans le système; la méthodologie développée dans cette partie permet d'étendre le langage de types et le langage de programmation en conservant un critère de consistance assurant la sûreté du code typé

Preuves, types et sous-types

Cette thèse porte sur l'étude théorique et pratique d'un système de typage appliqué à la preuve de programmes de style fonctionnels. Le système de base est le système ST créé par C.Raffalli; il comporte, outre le polymorphisme, du sous-typage et de l'omission de contenu non-algorithmique. Nous étudions tout d'abord les modèles de la théorie définie par le système de types, en construisant une axiomatique basée sur les treillis permettant de modéliser le calcul et la logique. Nous étudions sur cette base le système de types, montrons la réduction du sujet, et la possibilité de définir en interne la normalisabilité et la réductibilité des programmes. Dans la suite de la thèse, plus appliquée, nous étudions des codages de types de données riches inspirés des langages fonctionnels -y incluant notamment un système de modules du premier ordre- dans le Lambda- Calcul, et montrons qu'ils s'intègrent harmonieusement dans le système; la méthodologie développée dans cette partie permet d'étendre le langage de types et le langage de programmation en conservant un critère de consistance assurant la sûreté du code typéThis thesis is about the theoretical and practical study of a type system applied to functionnal programming certification. The base system is system ST invented by C.Raffalli; this system embeds polymorphism, subtyping and omission of non-algorithmic content. We firstly study models of this theory defined by the type system, building an axiomatic basis based on lattices that allows to express both calculus and logic. On this base, we study the type system itself, prove subject reduction, and the possibility of defining inside the system normalisability and reducibility properties. In the continuation, more applied, we study encoding of rich datatypes inspired from functional languages -including first-order modules- into Lambda-Calculus, and show that they behave well in the system through an embedding. The methodology of this part allows to extend the language preserving a consistency criterion ensuring the safety of the typed codeCHAMBERY -BU Bourget (730512101) / SudocSudocFranceF

Realizability of the axiom of choice in HOL. (An analysis of Krivine’s work)

This paper is an introduction to recent works in realizability, mainly Krivine’s work to realize the dependent choice axiom. We also show how to improve programs extracted from classical proofs by distinguishing formulas with and without algorithmic contents.

Experimental study of steady and transient subcooled flow boiling

International audienceThis study aims to better characterize the heat transfer and flow structure in the fully developed nucleate flow boiling regime in a semi-annular duct. Experiments with a refrigerant HFE7000 were performed in the range of Reynolds numbers from 13 000 to 40 500, subcoolings close to 15 ◦C, for constant heating power, constant wall temperature and constant heating rates (linear increase of the wall temperature). With constant heating power, the wall heat flux is well predicted by a Chen-type correlation based on a contribution due to the forced convection and a contribution due to nucleate boiling, including the effect of the liquid subcooling. A thin layer of bubbles sliding along the wall is observed. The characteristic diameter of the bubbles increases with the heat flux and decreases with the liquid velocity and its subcooling. The bubble diameters can be well predicted versus 3 dimensionless numbers: the Reynolds number of the flow, the Jakob number based on the liquid subcooling and the Boiling number. A drag coefficient of the bubbles sliding on the wall is estimated from the measurements of the bubble relative velocities and is in good agreement with the recent numerical simulation of Shi et al. [1] for a spherical bubble moving close to a wall in a shear flow. In the experiments with a constant set temperature, a non-homogeneity of the surface temperatures is observed as well as high fluctuations of temperatures and heat fluxes. The heat transfer is strongly degraded ( ????-60%) by comparison with heating with a set power. Finally a transient nucleate boiling regime with a constant temperature increase dT/dt is investigated. For dT/dt < 50 K.s−1, the results are similar to those of Auracher and Marquardt and a correlation for the prediction of the wall heat flux versus the wall temperature in the transient nucleate boiling regime is provided