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Séance de cours

Calcul du déplacement infinitésimal à la surface de la Terre

Concepts associés (26)

Spherical basis

In pure and applied mathematics, particularly quantum mechanics and computer graphics and their applications, a spherical basis is the basis used to express spherical tensors. The spherical basis closely relates to the description of angular momentum in quantum mechanics and spherical harmonic functions. While spherical polar coordinates are one orthogonal coordinate system for expressing vectors and tensors using polar and azimuthal angles and radial distance, the spherical basis are constructed from the standard basis and use complex numbers.

Line element

In geometry, the line element or length element can be informally thought of as a line segment associated with an infinitesimal displacement vector in a metric space. The length of the line element, which may be thought of as a differential arc length, is a function of the metric tensor and is denoted by . Line elements are used in physics, especially in theories of gravitation (most notably general relativity) where spacetime is modelled as a curved Pseudo-Riemannian manifold with an appropriate metric tensor.

Infinitesimal strain theory

In continuum mechanics, the infinitesimal strain theory is a mathematical approach to the description of the deformation of a solid body in which the displacements of the material particles are assumed to be much smaller (indeed, infinitesimally smaller) than any relevant dimension of the body; so that its geometry and the constitutive properties of the material (such as density and stiffness) at each point of space can be assumed to be unchanged by the deformation.

Traitement numérique du signal

Le traitement numérique du signal étudie les techniques de traitement (filtrage, compression, etc), d'analyse et d'interprétation des signaux numérisés. À la différence du traitement des signaux analogiques qui est réalisé par des dispositifs en électronique analogique, le traitement des signaux numériques est réalisé par des machines numériques (des ordinateurs ou des circuits dédiés). Ces machines numériques donnent accès à des algorithmes puissants, tel le calcul de la transformée de Fourier.

Convertisseur numérique-analogique

Un convertisseur numérique-analogique (CNA, de N/A pour numérique vers analogique ou, en anglais, DAC, de D/A pour Digital to Analog Converter) est un composant électronique dont la fonction est de transformer une valeur numérique (codée sur plusieurs bits) en une valeur analogique proportionnelle à la valeur numérique codée. Généralement la sortie du convertisseur est une tension électrique, mais certains convertisseurs ont une sortie en courant. N/A = Fréquence / Bits Il existe plusieurs solutions pour créer un signal analogique à partir d'un système numérique.

Linear elasticity

Linear elasticity is a mathematical model of how solid objects deform and become internally stressed due to prescribed loading conditions. It is a simplification of the more general nonlinear theory of elasticity and a branch of continuum mechanics. The fundamental "linearizing" assumptions of linear elasticity are: infinitesimal strains or "small" deformations (or strains) and linear relationships between the components of stress and strain. In addition linear elasticity is valid only for stress states that do not produce yielding.