A Calculus of Interfaces for Distributed Collaborative Systems: The Guarded Attribute Grammar Approach

International audience We address the problem of component reuse in the context of service-oriented programming and more specifically for the design of user-centric distributed collaborative systems modelled by Guarded Attribute Grammars. Following the contract-based specification of components we devel-opp an approach to an interface theory for the components of a collaborative system in three stages: we define a composition of interfaces that specifies how the component behaves with respect to its environement, we introduce an implementation order on interfaces and finally a residual operation on interfaces characterizing the systems that, when composed with a given component, can complement it in order to realize a global specification. Nous abordons le problème de la réutilisation des composants dans le contexte de la programmation orientée services et plus spécifiquement pour la conception de systèmes collaboratifs distribués centrés sur l'utilisateur modélisés par des grammaires attribuées gardées. En suivant la démarche de la spécification contractuelle des composants, nous développons une approche de la théorie des interfaces pour les composants d'un système collaboratif en trois étapes: on définit une composition d'interfaces qui spécifie comment le composant se comporte par rapport à son environnement, on introduit un ordre d'implémentation sur les interfaces et enfin une opération de résidus sur les interfaces qui caractérise les systèmes qui, lorsqu'ils sont composés avec un composant donné, peuvent le compléter afin de réaliser une spécification du système global.

Feasibility of Using Grammars to Infer Room Semantics

Current indoor mapping approaches can detect accurate geometric information but are incapable of detecting the room type or dismiss this issue. This work investigates the feasibility of inferring the room type by using grammars based on geometric maps. Specifically, we take the research buildings at universities as examples and create a constrained attribute grammar to represent the spatial distribution characteristics of different room types as well as the topological relations among them. Based on the grammar, we propose a bottom-up approach to construct a parse forest and to infer the room type. During this process, Bayesian inference method is used to calculate the initial probability of belonging an enclosed room to a certain type given its geometric properties (e.g., area, length, and width) that are extracted from the geometric map. The approach was tested on 15 maps with 408 rooms. In 84% of cases, room types were defined correctly. It, to a certain degree, proves that grammars can benefit semantic enrichment (in particular, room type tagging).