Decompression equipmentThere are several categories of decompression equipment used to help divers decompress, which is the process required to allow divers to return to the surface safely after spending time underwater at higher ambient pressures. Decompression obligation for a given must be calculated and monitored to ensure that the risk of decompression sickness is controlled. Some equipment is specifically for these functions, both during planning before the dive and during the dive.
Grammaire de dépendanceOn désigne par grammaire de dépendance une approche de la syntaxe fondée par Lucien Tesnière. Elle se distingue par la place centrale donnée à une structure hiérarchique, appelée Stemma par Lucien Tesnière, mais plus connue aujourd'hui sous le terme d’arbre de dépendance. L'arbre de dépendance est un arbre, au sens mathématique du terme, représentant les liens syntaxiques entre les mots d'une phrase. Les grammaires de dépendance ne réfèrent donc pas à un cadre théorique restreint, mais la notion de dépendance peut être explicite ou implicite dans la formalisation des règles syntaxiques.
Decompression theoryDecompression theory is the study and modelling of the transfer of the inert gas component of breathing gases from the gas in the lungs to the tissues and back during exposure to variations in ambient pressure. In the case of underwater diving and compressed air work, this mostly involves ambient pressures greater than the local surface pressure, but astronauts, high altitude mountaineers, and travellers in aircraft which are not pressurised to sea level pressure, are generally exposed to ambient pressures less than standard sea level atmospheric pressure.
Definite clause grammarA definite clause grammar (DCG) is a way of expressing grammar, either for natural or formal languages, in a logic programming language such as Prolog. It is closely related to the concept of attribute grammars / affix grammars from which Prolog was originally developed. DCGs are usually associated with Prolog, but similar languages such as Mercury also include DCGs. They are called definite clause grammars because they represent a grammar as a set of definite clauses in first-order logic.
Functional discourse grammarFunctional grammar (FG) and functional discourse grammar (FDG) are grammar models and theories motivated by functional theories of grammar. These theories explain how linguistic utterances are shaped, based on the goals and knowledge of natural language users. In doing so, it contrasts with Chomskyan transformational grammar. Functional discourse grammar has been developed as a successor to functional grammar, attempting to be more psychologically and pragmatically adequate than functional grammar.
Lossy compressionIn information technology, lossy compression or irreversible compression is the class of data compression methods that uses inexact approximations and partial data discarding to represent the content. These techniques are used to reduce data size for storing, handling, and transmitting content. The different versions of the photo of the cat on this page show how higher degrees of approximation create coarser images as more details are removed. This is opposed to lossless data compression (reversible data compression) which does not degrade the data.
Accident de décompressionOn appelle accident de décompression (ADD) les conséquences immédiates pour la santé de la formation de bulles gazeuses dans le corps à la suite d'une baisse rapide de la pression environnante. Il peut s'agir d'un accident de plongée, mais il survient aussi chez des personnes ayant travaillé dans des caissons en air comprimé, chez des aviateurs en altitude, ou chez des astronautes après une sortie extravéhiculaire. C'est une conséquence de la loi de Henry : la quantité de gaz dissout dans un liquide (ici, l'azote ou hélium dans le sang) est proportionnelle à la pression subie par le liquide.
Parsing expression grammarIn computer science, a parsing expression grammar (PEG) is a type of analytic formal grammar, i.e. it describes a formal language in terms of a set of rules for recognizing strings in the language. The formalism was introduced by Bryan Ford in 2004 and is closely related to the family of top-down parsing languages introduced in the early 1970s. Syntactically, PEGs also look similar to context-free grammars (CFGs), but they have a different interpretation: the choice operator selects the first match in PEG, while it is ambiguous in CFG.
Categorial grammarCategorial grammar is a family of formalisms in natural language syntax that share the central assumption that syntactic constituents combine as functions and arguments. Categorial grammar posits a close relationship between the syntax and semantic composition, since it typically treats syntactic categories as corresponding to semantic types. Categorial grammars were developed in the 1930s by Kazimierz Ajdukiewicz and in the 1950s by Yehoshua Bar-Hillel and Joachim Lambek.
Compression d'imageLa compression d'image est une application de la compression de données sur des . Cette compression a pour utilité de réduire la redondance des données d'une image afin de pouvoir l'emmagasiner sans occuper beaucoup d'espace ou la transmettre rapidement. La compression d'image peut être effectuée avec perte de données ou sans perte. La compression sans perte est souvent préférée là où la netteté des traits est primordiale : schémas, dessins techniques, icônes, bandes dessinées.
