ACCESS TO SPECIFIC DECLARATIVE KNOWLEDGE BY EXPERT SYSTEMS: THE IMPACT OF LOGIC PROGRAMMING

As part of the operation of an Expert System, a deductive component accesses a database of facts to help simulate the behavior of a human expert in a particular problem domain. The nature of this access is examined, and four access strategies are identified. Features of each of these strategies are addressed within the framework of a Logic-based deductive component and the relational model of data.Information Systems Working Papers Serie

Combining Relational Algebra, SQL, Constraint Modelling, and Local Search

The goal of this paper is to provide a strong integration between constraint modelling and relational DBMSs. To this end we propose extensions of standard query languages such as relational algebra and SQL, by adding constraint modelling capabilities to them. In particular, we propose non-deterministic extensions of both languages, which are specially suited for combinatorial problems. Non-determinism is introduced by means of a guessing operator, which declares a set of relations to have an arbitrary extension. This new operator results in languages with higher expressive power, able to express all problems in the complexity class NP. Some syntactical restrictions which make data complexity polynomial are shown. The effectiveness of both extensions is demonstrated by means of several examples. The current implementation, written in Java using local search techniques, is described. To appear in Theory and Practice of Logic Programming (TPLP)Comment: 30 pages, 5 figure

Using natural language for database queries

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Making object-oriented databases more knowledgeable (From ADAM to ABEL)

Tesis leida en la Universidad de Aberdeen. 178 p.The salient points of this thesis are as follows: • Object-Oriented Databases can help in solving the impedance mismatch problem by introducing methods. However, methods have sometimes been overused in the sense th at the code encapsulated refers not only to how the operation is implemented but also to other kinds of knowledge that are implicit in the code. The disadvantages of this approach for modelling integrity constraints, user-defined relationships and active behaviour are pointed out. • The ADAM Object-Oriented Database has been extended to allow the designer to specify integrity constraints declaratively. A constraint equation approach is implemented th at supports the inheritance of constraints. • A need for semantic-rich user-defined relationships has been identified. In this thesis, relationships are represented as objects. An approach to enhance the semantics of relationships in both its structural and behavioural aspects is presented. The most novel idea of the approach presented is the support of the inferred properties and the operational semantics of relationships. • Active Databases have recently become an im portant area of research. This thesis shows how to extend an Object-Oriented Database with active capabilities. The principal contribution lies in representing as ‘first-class’ objects not only the active rules but also the rule manager itself. Hence, besides handling active rules as any other object in the system, future requirements can be supported just by specialising the current rule manager. • Active rules have been proposed for several purposes. Several examples, are given of the direct use of rules. However, higher level tools can be provided of which rule

An intelligent Geographic Information System for design

Recent advances in geographic information systems (GIS) and artificial intelligence (AI) techniques have been summarised, concentrating on the theoretical aspects of their construction and use. Existing projects combining AI and GIS have also been discussed, with attention paid to the interfacing methods used and problems uncovered by the approaches. AI and GIS have been combined in this research to create an intelligent GIS for design. This has been applied to off-shore pipeline route design. The system was tested using data from a real pipeline design project. [Continues.

Third Conference on Artificial Intelligence for Space Applications, part 1

The application of artificial intelligence to spacecraft and aerospace systems is discussed. Expert systems, robotics, space station automation, fault diagnostics, parallel processing, knowledge representation, scheduling, man-machine interfaces and neural nets are among the topics discussed