Noureddine Mouaddib

Management of uncertainty and vagueness in databases: the firms point of view

In this paper, we present an approach to model and retrieve nuanced information (i.e. uncertain, fuzzy and incomplete information). The particularities of the model we propose are: • the introduction of the nuanced value concept to distinguish between a value (ex: young) and a nuance which is a complement on value and either expresses uncertainty (e.g. probably, …) or linguistic quantifiers/modifiers (e.g. very, often,…). • the possibility to represent aggregate attributes (i.e. attribute composed with a set of attributes) and to generate their values from nuanced value of the component attributes. • the advantage to define nuanced domain which is the set of all possible associations value/nuance for an attribute. We will show that a nuanced domain is an extension of the linguistic variable notion introduced by Zadeh. • the use of: (i) the fuzzy thesaurus concept to constraint values of discret attributes; (ii) an associated grammar of Chomsky to generate automatically the characteristic functions of the thesaurus terms. An interactive and progressive process is proposed to retrieve information taking into account fuzzy thesaurus and nuanced information. These propositions are implemented into FIRMS system that we realize in Smalltalk language.

Semantics of user interface for image retrieval: possibility theory and learning techniques

A spark erosion machine having a machine table fixed to the machine upright and on which can be arranged a working container for the dielectric fluid by joining a vertically movable, cross-sectionally C-shaped component to an L-shaped component in longitudinal section. The L-shaped component comprises a fixed vertical wall element forming the rear wall of the working container and the machine table plate, which is detachably connected to the fixed wall element through a seal. The machine table plate is fixable in the reference plane of the machine table by means of rapid fastening and centering devices.

Handling of Fuzzy Information in an Object Oriented Environment

Most database models are extended to fuzzy database models for managing and retrieving imperfect information. In recent years, considerable attention was focused on the relational data model but more recently greater attention is being turned to the investigation of object-oriented data models. The incorporation of these research results into commercial relational databases management systems (RDBMS) has not as yet a reality. The main reason for this has to do with the rigidity/inflexibility of actual RDBMS. New generation object-oriented databases management systems (OODBMS) offer greater possibilities for incorporating imperfect information thanks to the reusability and extensibility properties of OODBMS. Strategic information systems of the 1990’s should be able to deal with nuanced information, i.e. imprecision, uncertainty, subjective characteristics of economic and sociological data. In this paper, we propose a solution for the representation of fuzzy information in an object-oriented environment. The solution offers facilities for defining membership functions necessary for managing fuzzy information and for retrieving objects close to an established profile in a complex objects base. The economic sciences serve as testing ground for these concepts.

A semi-structured object model with relations

This paper introduces a semi-structured object model based on a weak notion of object classes, named categories. In our model, a category holds common properties of a set of objects. An object in our model may have features of its own, not abstracted in the category to which they belong; hence the semi-structured nature of the model. This feature of the model is very useful in domains where object structures can not be easily abstracted in classes. Besides, object structures in our model are based on object components and internal relationships between them. Relationships are only used to enrich the description of objects, by specifying links between their components, thus, they are properties of the main object and not of those components. This approach makes it possible to represent contextual relationships (that are valid only in the context of the main object). It also insures information localization (within the main object) which is an important feature of object orientation. A suited query language has been defined. Queries are specified in the same way as objects.

Management of complex attributes with fuzzy values in databases

In the present work we attempt to extension an object oriented data model to: 1) describe fuzzy objects with a new attribute type which we call a fuzzy complex attribute, where a complex attribute can be either calculated (i.e., its value is calculated from values of other attributes) or aggregated (i.e., it is composed by a set of attributes) and all the manipulated values can be fuzzy; 2) extend the retrieval process with the new attribute type in order to allow more flexibility in queries. The approach we propose is illustrated by a real example in human resources management.<<ETX>>

Object-oriented approach to design a content-based image retrieval model

The objective of this article is to offer both an image description model in three levels and an adapted image retrieval process. The proposed model allows the description of: the image globally with a classical manner (a list of concepts); the objects separately contained in the image (component objects); and relations between the component objects. This allows more semantic aspects of the image structure to be expressed. It is also possible to use fuzzy information in each level of the description. To build this model, we used the concepts of the object-oriented approach: generalization/specialization, aggregation, and inheritance. This approach is born from a strong need expressed in several fields such as medicine, CAD/CAM, architecture, and the teledetection industry, to be able to retrieve and describe images, their component objects, and the relations between them more precisely, with their own vocabulary and concepts.