22 research outputs found
Quels formalismes temporels pour représenter des connaissances extraites de textes de recettes de cuisine ?
National audienceThe Taaable projet goal is to create a case-based reasoning system for retrieval and adaptation of cooking recipes. Within this framework, we are discussing the temporal aspects of recipes and the means of representing those in order to adapt their text.Le projet Taaable a pour objet de construire un système de raisonnement à partir de cas pour la recherche et l'adaptation de textes de recettes de cuisine. Dans ce cadre, nous nous intéressons aux aspects temporels des recettes et à la manière de les représenter afin d'en envisager l'adaptation textuelle
Classification topologique des ensembles convexes de Allen
10 pagesInternational audienceReprésenter et raisonner sur des informations temporelles qualitatives, incomplètes et imprécises constitue une partie essentielle de nombreux travaux en intelligence artificielle. Les modèles de représentation de ces informations temporelles reposent soit sur le concept d'intervalle, soit sur celui de point. Raisonner dans l'algèbre d'intervalle d'Allen est un problème connu comme NP-difficile. C'est pourquoi la recherche de sous-classes traitables est si importante. La classe traitable la plus utilisée, dû au concept cognitif de voisinage, est la classe des 83 relations convexes, ensemble des relations de Allen traduisibles en conjonction d'inéquations linéaires sur l'ensemble de leurs extrémités (points). Nous proposons dans cet article, une taxonomie de cette sous-classe fondée sur l'ensemble des ordres sur au plus 4 points préservant la notion d'intervalle. Nous en avons déduit un outil graphique d'aide à la spécification et à la résolution des contraintes temporelles qualitatives
A Modal Logic for Subject-Oriented Spatial Reasoning
We present a modal logic for representing and reasoning about space seen from the subject\u27s perspective. The language of our logic comprises modal operators for the relations "in front", "behind", "to the left", and "to the right" of the subject, which introduce the intrinsic frame of reference; and operators for "behind an object", "between the subject and an object", "to the left of an object", and "to the right of an object", employing the relative frame of reference. The language allows us to express nominals, hybrid operators, and a restricted form of distance operators which, as we demonstrate by example, makes the logic interesting for potential applications. We prove that the satisfiability problem in the logic is decidable and in particular PSpace-complete
What is a Qualitative Calculus? A General Framework
What is a qualitative calculus? Many qualitative spatial and temporal calculi arise from a set of JEPD (jointly exhaustive and pairwise disjoint) relations: a stock example is Allen's calculus, which is based on thirteen basic relations between interval
An integrated first-order theory of points and intervals : expressive power in the class of all linear orders
There are two natural and well-studied approaches to temporal ontology and reasoning, that is, pointbased and interval-based. Usually, interval-based temporal reasoning deals with points as a particular case of duration-less intervals. Recently, a two-sorted point-interval temporal logic in a modal framework in which time instants (points) and time periods (intervals) are considered on a par has been presented. We consider here two-sorted first-order languages, interpreted in the class of all linear orders, based on the same principle, with relations between points, between intervals, and intersort. First, for those languages containing only interval-interval, and only inter-sort relations we give complete classifications of their sub-fragments in terms of relative expressive power, determining how many, and which, are the different two-sorted first-order languages with one or more such relations. Then, we consider the full two-sorted first-order logic with all the above mentioned relations, restricting ourselves to identify all expressively complete fragments and all maximal expressively incomplete fragments, and posing the basis for a forthcoming complete classification
An Integrated First-Order Theory of Points and Intervals over Linear Orders (Part II)
There are two natural and well-studied approaches to temporal ontology and
reasoning: point-based and interval-based. Usually, interval-based temporal
reasoning deals with points as a particular case of duration-less intervals. A
recent result by Balbiani, Goranko, and Sciavicco presented an explicit
two-sorted point-interval temporal framework in which time instants (points)
and time periods (intervals) are considered on a par, allowing the perspective
to shift between these within the formal discourse. We consider here two-sorted
first-order languages based on the same principle, and therefore including
relations, as first studied by Reich, among others, between points, between
intervals, and inter-sort. We give complete classifications of its
sub-languages in terms of relative expressive power, thus determining how many,
and which, are the intrinsically different extensions of two-sorted first-order
logic with one or more such relations. This approach roots out the classical
problem of whether or not points should be included in a interval-based
semantics. In this Part II, we deal with the cases of all dense and the case of
all unbounded linearly ordered sets.Comment: This is Part II of the paper `An Integrated First-Order Theory of
Points and Intervals over Linear Orders' arXiv:1805.08425v2. Therefore the
introduction, preliminaries and conclusions of the two papers are the same.
This version implements a few minor corrections and an update to the
affiliation of the second autho
Adaptation de cas spatiaux et temporels
National audienceQualitative algebras form a family of languages mainly used to represent knowledge depending on space or time. This paper proposes an approach to adapt cases represented in such an algebra. A spatial example in agronomy and a temporal example in cooking are given. The idea behind this adaptation approach is to apply a substitution and then repair potential inconsistencies, thanks to belief revision on qualitative algebras.Les algèbres qualitatives forment une famille de langages utilisés principalement pour représenter des connaissances de nature temporelle ou spatiale. Cet article propose une approche pour adapter des cas représentés dans une telle algèbre. Un exemple spatial portant sur l'agronomie ainsi qu'un exemple temporel portant sur la cuisine sont donnés. L'idée sous-jacente à cette approche de l'adaptation est d'appliquer une substitution puis de réparer les incohérences qui pourraient être apparues, grâce à la révision des croyances appliquée aux algèbres qualitatives