BoostingLe boosting est un domaine de l'apprentissage automatique (branche de l'intelligence artificielle). C'est un principe qui regroupe de nombreux algorithmes qui s'appuient sur des ensembles de classifieurs binaires : le boosting optimise leurs performances. Le principe est issu de la combinaison de classifieurs (appelés également hypothèses). Par itérations successives, la connaissance d'un classifieur faible - weak classifier - est ajoutée au classifieur final - strong classifier.
Multi-task learningMulti-task learning (MTL) is a subfield of machine learning in which multiple learning tasks are solved at the same time, while exploiting commonalities and differences across tasks. This can result in improved learning efficiency and prediction accuracy for the task-specific models, when compared to training the models separately. Early versions of MTL were called "hints". In a widely cited 1997 paper, Rich Caruana gave the following characterization:Multitask Learning is an approach to inductive transfer that improves generalization by using the domain information contained in the training signals of related tasks as an inductive bias.
Système multi-agentsEn informatique, un système multi-agent (SMA) est un système composé d'un ensemble d'agents (un processus, un robot, un être humain, une fourmi etc.), actifs dans un certain environnement et interagissant selon certaines règles. Un agent est une entité caractérisée par le fait qu'elle est, au moins partiellement, autonome, ce qui exclut un pilotage centralisé du système global.
Exponential utilityIn economics and finance, exponential utility is a specific form of the utility function, used in some contexts because of its convenience when risk (sometimes referred to as uncertainty) is present, in which case expected utility is maximized. Formally, exponential utility is given by: is a variable that the economic decision-maker prefers more of, such as consumption, and is a constant that represents the degree of risk preference ( for risk aversion, for risk-neutrality, or for risk-seeking).
Radial basis function networkIn the field of mathematical modeling, a radial basis function network is an artificial neural network that uses radial basis functions as activation functions. The output of the network is a linear combination of radial basis functions of the inputs and neuron parameters. Radial basis function networks have many uses, including function approximation, time series prediction, classification, and system control. They were first formulated in a 1988 paper by Broomhead and Lowe, both researchers at the Royal Signals and Radar Establishment.
Covariance functionIn probability theory and statistics, the covariance function describes how much two random variables change together (their covariance) with varying spatial or temporal separation. For a random field or stochastic process Z(x) on a domain D, a covariance function C(x, y) gives the covariance of the values of the random field at the two locations x and y: The same C(x, y) is called the autocovariance function in two instances: in time series (to denote exactly the same concept except that x and y refer to locations in time rather than in space), and in multivariate random fields (to refer to the covariance of a variable with itself, as opposed to the cross covariance between two different variables at different locations, Cov(Z(x1), Y(x2))).
Classifieur linéaireEn apprentissage automatique, les classifieurs linéaires sont une famille d'algorithmes de classement statistique. Le rôle d'un classifieur est de classer dans des groupes (des classes) les échantillons qui ont des propriétés similaires, mesurées sur des observations. Un classifieur linéaire est un type particulier de classifieur, qui calcule la décision par combinaison linéaire des échantillons. « Classifieur linéaire » est une traduction de l'anglais linear classifier.
Decision stumpA decision stump is a machine learning model consisting of a one-level decision tree. That is, it is a decision tree with one internal node (the root) which is immediately connected to the terminal nodes (its leaves). A decision stump makes a prediction based on the value of just a single input feature. Sometimes they are also called 1-rules. Depending on the type of the input feature, several variations are possible.
