Search results for "formal"
showing 10 items of 1654 documents
Some Computational Aspects of DISTANCE-SAT
2007
In many AI fields, one must face the problem of finding a solution that is as close as possible to a given configuration. This paper addresses this problem in a propositional framework. We introduce the decision problem distance-sat, which consists in determining whether a propositional formula admits a model that disagrees with a given partial interpretation on at most d variables. The complexity of distance-sat and of several restrictions of it are identified. Two algorithms based on the well-known Davis/Logemann/Loveland search procedure for the satisfiability problem sat are presented so as to solve distance-sat for CNF formulas. Their computational behaviors are compared with the ones …
How to Enrich Description Logics with Fuzziness
2017
International audience; The paper describes the relation between fuzzy and non-fuzzy description logics. It gives an overview about current research in these areas and describes the difference between tasks for description logics and fuzzy logics. The paper also deals with the transformation properties of description logics to fuzzy logics and backwards. While the process of transformation from a description logic to a fuzzy logic is a trivial inclusion, the other way of reducing information from fuzzy logic to description logic is a difficult task, that will be topic of future work.
Attempts to produce minimal Resolution refutations
2018
We address the challenge of searching minimal refutations proofs of inconsistent CNF formulae using the Resolution rule. We propose two algorithms which can only afford formulae of at most 5 variables with a desktop computer. A faster but incomplete algorithm is used to produce "hard" 5 variables 3CNF formulae though a stochastic greedy search. It allowed us to find formulae that can be refuted by producing clauses of at most 3 literals, but whose all minimal refutations contain at least one clause of 4 literals.
Architectural Reconstruction of 3D Building Objects through Semantic Knowledge Management
2010
International audience; This paper presents an ongoing research which aims at combining geometrical analysis of point clouds and semantic rules to detect 3D building objects. Firstly by applying a previous semantic formalization investigation, we propose a classification of related knowledge as definition, partial knowledge and ambiguous knowledge to facilitate the understanding and design. Secondly an empirical implementation is conducted on a simplified building prototype complying with the IFC standard. The generation of empirical knowledge rules is revealed and semantic scopes are addressed both in the bottom up manner along the line of geometry --> topology --> semantic, and a vice ver…
Topological properties of cellular automata on trees
2012
We prove that there do not exist positively expansive cellular automata defined on the full k-ary tree shift (for k>=2). Moreover, we investigate some topological properties of these automata and their relationships, namely permutivity, surjectivity, preinjectivity, right-closingness and openness.
Propose Semantic Formalization for 3D Reconstruction of Architectural
2010
International audience; Archi3D project is a successful practice well proved by engineering practices. In this paper, we propose to reconstruct semantics for the purpose of reconstruct 3D architecture in Archi3D fundamentally. The formalization approach starts from several hypotheses on semantics which include: there is a core mechanism of semantics which is not limited to conceptual expression level; and a complete expression of semantics necessaries the ―implicitexplicit‖ transition of human side knowledge, etc. The necessity and feasibility concerning applying the proposed method and technology to the practice of Archi3D is discussed systemically by way of semantics revelations on some …
Semantics knowledge management for the 3D architectural reconstruction of building objects
2010
International audience; This paper presents the framework of an ongoing semantics knowledge management practice. The practice combines geometrical analysis of point cloud and semantic rules to detect 3D building objects for the purpose of achieving computational correctness and efficiency. We assume that improvement in the form of well organized classification (CLA) and order (ORD) is a solution. Statically related knowledge is classified as definition, partial knowledge and ambiguous knowledge and formally revealed with transitions between CWA (closed world assumption) and OWA (open world assumption). To achieve the correctness, formalization is proposed for the validation of the rules thr…
Managing semantics knowledge for 3D architectural reconstruction
2010
International audience; this work aims at bound geometrical detection of 3D objects from a point cloud using semantic descriptors to improve reusability of architectural building reconstruction and aid automatic reasoning in building information modeling (BIM). Based on exploring cognitive origins of spatial semantics representations, semantics conceptualization and classification is proposed for formal management of 3D architectural objects. The knowledge classification composes definition, partial knowledge and ambiguous knowledge, and is formalized with transformations among closed world assumption (CWA) and open world assumption (OWA). Systemic case study is conducted on a simplified bu…
Formalizing Semantic of Natural Language through Conceptualization from Existence
2011
International audience; We propose an outline of an approach to formalize semantic from conceptualization for both natural language (NL) and logic expression mechanisms. This goes beyond the level of discussions at conceptual level which has to either end in conscious/unconscious relativity of understanding or subjective enforcement in the form of definitions instead of expected objective semantic. This approach supports to view from a pure mathematical perspective, and explore and locate the fundamental problems. The semantic formalization mechanism realizes the integration of problem description and the solution expression at absolute semantic level. So a problem describing process is equ…
COBieOWL, an OWL ontology based on COBie standard
2015
International audience; Building Information Modelling (BIM) standards have been recognized by construction and political actors as a highly promising tool for resolving issues of data dematerialization, notably in the field of Architecture, Engineering, Construction and Facility Management. Among worldwide-adopted BIM standards, there is COBie. COBie’s goals are to dematerialize building data and to enhance building information interoperability. Nevertheless, COBie data is available in static formats such as STEP or spreadsheet templates. Such formats lack logical formalisms and semantic features provided by languages such as OWL. Because of this, in this paper, we propose a method for sem…