Search results for "Mathematica"
showing 10 items of 7971 documents
The constitution of the nature of mathematics in the lecturing practices of three university mathematics teachers
2015
International audience; The study reported in this paper investigates how notions of the nature of mathematical knowledge and mathematical objects are articulated in the discursive practices of three university mathematics teachers at a Swedish university. The data consists of video recorded lectures, and the analyses were informed by classifications presented by Lerman (1990) and Davis and Hersh (1981). The results indicate that different epistemological and ontological positions are indeed constituted through the discourse. Although the discourse is generally highly objectified, the ways in which mathematical objects are introduced differ. Mostly the discourse was within an ab-solutist pa…
Trustworthiness of information about students' competencies in fundamental concepts in calculus provided by written examination
2015
International audience; The research reported in this paper aims to explore how students' competencies in calculus are exposed when being assessed. Several different competencies are required to achieve proficiency in mathematics. However, one problem is when the main focus of the student lies within procedural fluency because this is what pays off in the final examination. In this paper, written examination and task-based interview are used to find information about one student's competence in using formulae, fluency in written procedures, and strategies used for solving tasks. It is argued that the information about the student's competencies seen through a task-based interview is differe…
University Governance and Finance: The Impact of Changes in Resource Allocation on Decision Making Structures
2002
When trying to account for changes that take place over time in the structure of any organisation, social scientists often use a conceptual framework known as resource dependency theory. This theory assumes that organisations survive only if they are able to react to changes that occur in the world around them in order to obtain the resources they need to stay in operation. Since they have the capacity for independent action, organisations are not passively shaped by their environment; they sometimes are also able to influence it.
Les migrations des basketteurs professionnels en Europe
2010
En Europe, les migrations des joueurs professionnels sont commandées par l’existence de deux centres de «production» et de «consommation», les États-Unis et l’Europe, et d’une immense périphérie. Comme pour le football, américanisation et mondialisation des recrutements sont partielles et les recrutements obéissent à des critères financiers, réglementaires, sportifs et géo-culturels.
Construction engineering and natural philosophy: the work by Gabriel Lamé
1995
We find Lame again, an other pupill of the “Ecole polytechnique” who considers again the analogy between the catenary and the thin vault stable under its own weight He improve the famous work of Coulomb who applies the theory of maximis and minimis to Architecture. Le scientific biography that follows shows a scientist who has been interrested in cristallography, elastic mediums, optics and heat, electricity and was convinced of the existence of a unitary theory in which an elastic ether would play a central role.
Symetry and its formalisms : mathematical aspects
2009
International audience; This article explores the relation between the concept of symmetry and its formalisms. The standard view among philosophers and physicists is that symmetry is completely formalized by mathematical groups. For some mathematicians however, the groupoid is a competing and more general formalism. An analysis of symmetry that justifies this extension has not been adequately spelled out. After a brief explication of how groups, equivalence, and symmetries classes are related, we show that, while it’s true in some instances that groups are too restrictive, there are other instances for which the standard extension to groupoids is too unrestrictive. The connection between gr…
Matrices de pondérations et contexte spatio-temporel en économétrie spatiale
2013
International audience
Numerical vibroacoustic analysis of plates with constrained-layer damping patches
2011
International audience; A numerical vibroacoustic model that can manage multilayered plates locally covered with damping patches is presented. All the layers can have an on-axis orthotropic viscoelastic behavior. Continuity of displacements and transverse shear stresses at each interface is enforced, which permits to write the entire displacement field in function of the displacements of the-common-first layer, leading to a two-dimensional plate model. The problem is then discretized by Rayleigh-Ritz's method using a trigonometric basis that includes both sine and cosine functions in order to treat various boundary conditions. The excitation can be of mechanical kind (concentrated or distri…
Acoustic Topological Circuitry in Square and Rectangular Phononic Crystals
2021
International audience; We systematically engineer a series of square and rectangular phononic crystals to create experimental realizations of complex topological phononic circuits. The exotic topological transport observed is wholly reliant upon the underlying structure which must belong to either a square or rectangular lattice system and not to any hexagonal-based structure. The phononic system chosen consists of a periodic array of square steel bars which partitions acoustic waves in water over a broadband range of frequencies (∼0.5MHz). An ultrasonic transducer launches an acoustic pulse which propagates along a domain wall, before encountering a nodal point, from which the acoustic si…
Excitons in few-layer hexagonal boron nitride: Davydov splitting and surface localization
2018
Hexagonal boron nitride (hBN) has been attracting great attention because of its strong excitonic effects. Taking into account few-layer systems, we investigate theoretically the effects of the number of layers on quasiparticle energies, absorption spectra, and excitonic states, placing particular focus on the Davydov splitting of the lowest bound excitons. We describe how the inter-layer interaction as well as the variation in electronic screening as a function of layer number $N$ affects the electronic and optical properties. Using both \textit{ab initio} simulations and a tight-binding model for an effective Hamiltonian describing the excitons, we characterize in detail the symmetry of t…