摘要:

Cartographic map overlay is the process of superimposing two maps into one to convey information in spatial correlation. A map refers to one in vector representation: a two‐dimensional spatial data structure of nodes, chains, and polygons. We present a map overlay system developed in Prolog. The system adopts a relational approach to data structuring. We represent geometric entities and their relationships as facts, and encode geometry algorithms in the rules. Set‐based operations perform data processing. To speed up the search for chain intersections, a uniform rectangular grid is imposed over the object space for spatial sorting by distribution. We sort out potentially intersecting edge segments to those occupying some common grid cell. Each bucket, if non‐empty, is implemented as a Prolog fact identifying the grid cell for random access. Geometric intersections are calculated using exact rational arithmetic implemented in Prolog. Numerical accuracy is preserved and we can identify all the special cases of tangent conditions. We can then guarantee topological consistency, and stability in the process of map overlay is therefore ach

ISSN:0824-7935    

DOI:10.1111/j.1467-8640.1990.tb00290.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

In this paper, we present an extension to PROLOG we call DISLOG which is designed to deal with relations between non‐contiguous elements in a structure. This extension turns out to be well suited for syntactic analysis of natural and artificial languages. It is also well adapted to express traversal constraints in applications such as planning and expert systems and deductive systems involving, for example, temporal reasoning, DISLOG belongs to the constrained logic programming paradigm and turns out to be more declarative, transparent, and simple than PROLOG to deal with longdistance relation

ISSN:0824-7935    

DOI:10.1111/j.1467-8640.1990.tb00291.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

A synergism has begun to surface from the artificial intelligence (AI) and engineering communities: an effort to apply AI techniques to engineering problem‐solving activities, and to study problems arisen from various engineering fields as a way to develop AI theories and methodologies. This paper first discusses the needs of such a synergical approach and identifies in a broad perspective some AI techniques currently being applied to engineering. It then describes a system, called KREATOR, which applies qualitative reasoning, a subfield of AI, to computer‐aided design (CAD). The key observation is that an engineer designer's qualitative knowledge can offer a good basis for the reasoning of device behaviors. Such knowledge, however, is not captured by conventional CAD systems for lack of good representations. KREATOR is a knowledge capturing scheme that allows the designers to record their qualitative knowledge of how mechanical devices behave, KREATOR then automatically generates qualitative simulati

ISSN:0824-7935    

DOI:10.1111/j.1467-8640.1990.tb00292.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

This paper presents a description of the application of an attributed graph based approach to the synthesis of a geometric world model for use in navigation by a mobile robot. Our aim is to develop the theoretical aspects of graph synthesis for mobile robot world knowledge acquisition, and to demonstrate the validity of the approach with a simulation before implementation on the rover. A boundary representation of free space consisting of directed line segments organized into a directed attributed graph is used. The synthesis problem can be considered as having two parts: matching of a local model with a global model and the construction of a new global model. Structural and geometric local and global constraints are used to limit and direct the search for valid graph mappings. The constraints are the source of rules for matching primitives and graphs and are used in the process of constructing a new world model graph. An algorithm for graph synthesis is implemented in a software simulation for testing and experimentation.

ISSN:0824-7935    

DOI:10.1111/j.1467-8640.1990.tb00293.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Temporal reasoning is essential for many artificial intelligence applications. To date, most research has concentrated on temporal inference in isolation without considering the role it can play in a more general reasoning environment. This paper takes an efficient temporal reasoner and extends its inferential capabilities to handle both strict and nonstrict relations. The resulting temporal specialist is incorporated into a system intended for low‐level reasoning in natural language understanding. The specialist assists the resolution‐based theorem prover in function evaluation, literal evaluation, and generalized resolving and factoring. The combined system can do some proofs in just a few steps that would normally require many. An example from the fully operational hybrid system is included.Le raisonnement temporel est essentiel dans de nombreuses applications relatives àľ intelligence artificielle. Jusqu’à présent, la plupart des travaux de recherche ont porté sur ľ inférence temporelle dans ľ isolation sans tenir compte du rǒle qu'elle peut jouer dans un environnement de raisonnement plus général. Cet article traite ? un raisonneur temporel ef ficace dont les capacityés inférentielles ont été augmentée afin de pouvoir traiter les relations strides et non strides. Le spécialiste temporel qui en résulte est intégréà un système conçu pour le raisonnement bas‐niveau en langage naturel. Le spécialiste assiste le démonstratur de théorèmes basé sur la résolution dans ľévaluation des fonctions, ľévaluation littérale et la fonction fadorielle généralisée. Le système combine peut vérifier des preuves en quelques étapes seulement au lieu ? un grand nombre. Un exemple ? un système hybride entièrement opérationnel est fourni.Mots clés: raisonnement temporel, methodes ? inférence spéciales, rés

ISSN:0824-7935    

DOI:10.1111/j.1467-8640.1990.tb00294.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY