Volume 17, 1998, No. 1


Interleaving Time and Structure

M. Balaban

Abstract. A model for knowledge representation that incorporates structure and time is presented. The model is the domain of structured histories, which is based on the interleaving of these features in a nested, structured manner. A rich temporal representation language is provided. The interleaving structure and time is shown to be fundamental to the representation of a variety of temporal domains, including planning, knowledge bases, and design. Applications in the areas of databases and music processing that are based on the structured histories ontology are summarized.

The novelty  of the approach presented in this paper is in the design of a general, domain independent, representation scheme for capturing the aspects of structure and time. As a result, both aspects can be declaratively specified in a single logical design, thereby providing a basis for well founded processing of structured - temporal domains.

 

Information Retrieval, Imaging and Probabilistic Logic

F. Sebastiani

Abstract. Imaging is a class of non-Bayesian methods for the revision  of probability density functions originally proposed as a semantics for conditional logic. Two of these revision functions, standard imaging and general imaging, have successfully been applied to modelling information retrieval by Crestani and van Rijsbergen.  Due to the problematic nature of a "direct" implementation of imaging revision functions, in this paper we propose their alternative implementation by representing the semantic structure that underlies imaging-based conditional logics in the language of a probabilistic (Bayesian) logic. Besides showing the potential of this "Bayesian" tool for the representation of non-Bayesian revision functions, recasting these models of information retrieval in such a general purpose knowledge representation and reasoning tool paves the way to a possible integration of these models with other more KR-oriented models, and to the exploitation of general-purpose domain-knowledge.

 

A Relationship Between the Probabilistic and the Possibilistic Logic

Do Van Thanh

Abstract. This paper points out that there exists a relationship between the principle of Maximal Entropy (ME) in probability theory and the principle of minimal Specificity (mS) in possibility theory via consistent transformations on sets of probability and possibility distributions. By using these transformations, the paper investigates the possibilities to apply methods of probabilistic logic for possibility knowledge bases and conversely, reasoning methods of possibilistic logic for probability knowledge bases.

 

Knowledge Extraction by a Fuzzy  Linguistic Summary Approach

Ding-An Chiang, Yi-Fan Wang, Wei Chen

Abstract. In some applications, it may be difficult to represent the exact meaning of an object due to the nature of the environment being modelled. Therefore, the object may only partially match certain properties, and crisp data mining approaches  may not be appropriate for this situation. To overcome the situation, a linguistic summary using the fuzzy set theory is developed as the data mining function in the KDD system. Using predefined properties, the proposed summary can answer the question "for each group in the database, which predefined property is shared by largest number of objects?", where  the property in the question could fall in the range F1 ÚÚ Fm rather than a single property, Fi.

 

Some Applications of Pedrycz's Operator

I. Iancu

Abstract. In this paper we give a general form of the expression of Pedrycz's  operator and then we show that this expression is useful to generate possibility and necessity measures and also to represent the vague and uncertain facts under the form of other vague and certain facts.


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