A PRE-ANALYSIS OF THE CREATION OF TEACHER RESOURCES FOR DEVELOPING INSTRUCTION IN BASIC LOGIC IN FRENCH HIGH SCHOOLS

If everyone agrees that logic is needed to do mathematics, there are divergences concerning the role of mathematical logic in acquiring the necessary and sufficient knowledge in this area. We will try first to see what might be the students' difficulties in the acquisition of logic of mathematics and what can be Mathematical Knowledge for Teaching Logic of mathematics. A study of syllabuses and textbooks for high school in France shows strong constraints and ill-defined conditions for this teaching. In their answers to a questionnaire we proposed, some teachers expressed their lack of theoretical knowledge in mathematical logic and lack of resources to present to their pupils activities in order to address notions of logic. During a continuous training, we try to offer an approach of mathematical logic which support teaching of logic of mathematics

Constitutive Damage Variable Measurement in Composites Using Guided Waves

Cohesive Zone Methods (CZMs) are numerical methods used to numerically simulate damage initiation and growth at the interfaces of composite materials under external loading. These techniques provide estimates of the residual properties of a damaged specimen such as residual strengths, fatigue life or stiffness losses. To run these simulations, it is necessary to measure material properties such as the strengths of the interfaces. To describe the state of the structure at a given time instant during the loading, CZMs define a damage variable D which is a constitutive variable of the structure assessing its current state of health. The literature has, so far, been focusing on the damage initiation and growth of standardized test samples or the modelization of high speed impact for example. This paper focuses on the measurement of the damage variable of a damaged test sample using guided waves. The measure of the damage variable of a specimen allows the creation of a numerical representation of the given specimen, leading to a customized set of residual properties estimation, thus removing the need to conduct extensive testing to characterize the residual strengths of materials. The technique developed in this paper relies on the Frequency Domain Instantaneous Wavenumber [2] technique, which is a guided wave-based technique measuring the wavenumber of propagating waves at every point of space from a single frequency steady state measurement. The measurement of the damage variable can be achieved regardless of the physical signification of defect, meaning that any defect weakening an interface of a composite can be modelled with different damage variable values, including delaminations, porous interfaces and wrinkles. After a short introduction of CZM, the fundamental relationship between the guided wave wavenumber and the damage variable is presented. The process, from the measurement of the non- destructive propagation of the guided waves to the estimation of the residual strengths is presented. The measure of various damage variable distributions is then presented for numerical simulations

Stability of Pseudo-Funicular Elastic Grid Shells

International audienceThe paper presents some results on the influence of the pre-stress induced by the erection method of elastic grid shells on their buckling capacity. It starts with the numerical methods and their validation with the study of a prebuckled arch. Then, a form-finding scheme using low-speed dynamics is used to generate automatically a family of elastic grid shells, and their buckling capacity is compared to the one of grid shells with the exact same geometry, but without any pre-stress. The paper demonstrates finally that the pre-stress decreases by a few percent the buckling capacity of elastic grid shells

Infirmières et ambulanciers: quelle collaboration optimale ? : travail de Bachelor

Notre sujet de travail de Bachelor a pour thème la collaboration entre les infirmières et les ambulanciers. Nous nous intéressons aux éléments qui pourraient influencer leur collaboration ainsi que les moyens qu’ils utilisent pour pourvoir fonctionner lors de leurs rencontres aux urgences

Möbius Geometry and Cyclidic Nets: A Framework for Complex Shape Generation

International audienceFree-form architecture challenges architects, engineers and builders. The geometrical rationalization of complex structures requires sophisticated tools. To this day, two frameworks are commonly used: NURBS modeling and mesh-based approaches. The authors propose an alternative modeling framework called generalized cyclidic nets that automatically yields optimal geometrical properties for the façade and the structure. This framework uses a base circular mesh and Dupin cyclides, which are natural objects of the geometry of circles in space, also known as Möbius geometry. This paper illustrates how new shapes can be generated from generalized cyclidic nets. Finally, it is demonstrated that this framework gives a simple method to generate curved-creases on free-forms. These findings open new perspectives for structural design of complex shells

Les stratégies de communication des protestants français

En dépit de caractéristiques qui pourraient passer pour des handicaps (minoritaires, divisés, réservés, disséminés…) les protestants français semblent communiquer de façon efficace. En réalité leurs fondements théologiques et ecclésiaux comportent également des atouts. Par ailleurs l’importance grandissante de la communication dans les entreprises et organisations les ont amenés à modifier profondément leurs modes d’intervention auprès des médias. De fait le protestantisme français communique maintenant avec des outils et des comportements professionnels autant qu’au coup par coup en amateur. Cette double démarche peut s’expliquer à la fois par la modestie des moyens matériels disponibles et par les réticences de certains de ses membres vis-à-vis d’attitudes qui bouleversent leur culture. Ce point de vue est conforté par la formidable progression des nouvelles technologies de l’information et de la communication. Elles ont pour conséquence une amplification de la réflexion des protestants français sur les défis et le bon usage des nouveaux médias.In spite of characteristics which could be construed as hindrances (they are a minority, they are divided, reserved, spread out…) French Protestants seem to able communicate in an efficient way. Actually, their theological and ecclesial bases also their assets. Furthermore, the growing importance of communication within companies and organisations has led them to modify in depth the ways in which they interact with the media. In fact, French Protestantism now communicate with professional tools and behaviours as well as, should the need arise, in an amteurish way. This double process can be explained both by the scantiness of the material means available to them and by the reservations some of theirs members have about attitudes which cause upheaval within their culture. These reservations are not subsiding with the extraordinary progression of the new information and communication technologies. As a result, the French Protestants reflexion on the challenges and the good uses of the new media is intensifying