摘要:

A method is presented of establishing bounds on the number of classification rules in such applications as credit worthiness assessment, investment decisions, premium determination, consumer choices, employee selection, and editorial preferences, to name just a few. A function that relates the maximum number of classification rules to the problem space size of such application domains is established. It is shown that in this important class of ordinal classification problems, the maximum possible number of rules is significantly lower than the relative problem space sizes. The approach grants the ability to a priori estimate worst case response time and memory requirements, and to better predict the effectiveness of knowledge acquisition efforts.

ISSN:0824-7935    

DOI:10.1111/j.1467-8640.1993.tb00299.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

This paper provides an extension to the study of the clause management system (CMS) proposed by Reiter and de Kleer. The CMS is adapted specifically for aiding a reasoning system in explanations generation. The reasoning system transmits propositional formulae representing its knowledge to the CMS and in return, it requests the CMS for minimal and consistent explanations of a query with respect to the CMS knowledge base. The CMS knowledge base is represented by a set of prime implicates. The classification of implicates as minimal, prime, trivial, and minimal trivial is carefully examined. Similarly, the notion of a support for a clause including minimal, prime, trivial, and minimal trivial is also elaborated. The methods to compute these supports from implicates and a preference ordering scheme expressible by logical specificity for the set of supports for a given clause are also presented. The generalization of the notion of a minimal support for a conjunction of clauses is also shown. Finally, two logic‐based diagnostic reasoning paradigms aided by the CMS are shown to exemplify the functionality of the CM

ISSN:0824-7935    

DOI:10.1111/j.1467-8640.1993.tb00300.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

This paper focuses on the semantics of Telos, a language for representing knowledge about information systems. Telos is intended to support the development of information systems, especially in the requirements modeling phase. An object‐oriented representational framework is supported by Telos. Its features includeaggregation, generalization,andclassification,the treatment of attributes as first‐class objects and the explicit representation of time. Telos also provides an assertion sublanguage for expressing deductive rules and integrity constraints. A possible‐worlds semantics is defined for Telos knowledge bases. This semantics is intended to capture the peculiarities involved in the interpretation of temporal expressions. The integration of time has also inspired the treatment ofexistencein Telos. An ontology of objects based on the property of existence is proposed. In the spirit of KRYPTON, Telos knowledge bases are specified functionally, in terms of the operations provided for querying and updating them. This knowledge‐level analysis will allow us to specify exactly what a knowledge base can be ASK‐ed or TELL‐ed about the domain of discourse. Soundness, consistency, and completeness results have also been proven to complete the specification of Telos knowledge bases. This formal account of the language provides a logical framework that can be used to verify the correctness of any proposed implementation of

ISSN:0824-7935    

DOI:10.1111/j.1467-8640.1993.tb00301.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Inheritance reasoners have traditionally been viewed as argument systems, or algorithms that determine reasonable conclusions by constructing acceptable arguments. While the intended meaning of links in such networks is understood, formal semantic accounts are troublesome, as are semantic accounts of the inference process. We adopt a different perspective, suggesting that links be interpreted as conditional sentences with appropriate truth conditions rather than uninterpreted “reasons.” The conditional logic CT4D is used for this purpose. Furthermore, we characterize inference in our networks in terms of preferred (or minimal) models. In the process, we identify some key differences between our account of inference and those based on the notion of inferential distance, specifically with respect to the stability of reasoning.Key words:nonmonotonic reasoning, inheritance hierarchies, minimal models, conditional lo

ISSN:0824-7935    

DOI:10.1111/j.1467-8640.1993.tb00302.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY