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We elaborate on the semantics of an enhanced object-oriented semantic network, where multiple instantiation, multiple specialization, and meta-classes are supported for both kinds of objects: entities and properties. By semantics of a semantic network, we mean the information (both explicit and derived) that the semantic network carries. Several da...
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We elaborate on the semantics of an enhanced object-oriented semantic network, where multiple instantiation, multiple specialization, and meta-classes are supported for both kinds of objects: entities and properties. By semantics of a semantic network, we mean the information (both explicit and derived) that the semantic network carries. Several da...
Covering is a well-known relationship in semantic and object-oriented data models. Covering holds when a class is the union of a collection of subclasses. However, covering has been studied only for entity classes. In this paper, we investigate covering for properties. We introduce a new relationship among properties, called property covering. Prop...
Citations
... The Semantic Index System (SIS) [24] is a persistent storage system based on the object-oriented semantic network data model Telos [30]. SIS-Telos data model [5] provides: unbounded classification hierarchy (metaschemata see schemata as data and allow to develop a schema under this specific discipline) multiple instantiation (one object-class can be instance of more than one classes using the attributes of all its classes-metaclasses), multiple inheritance, as well as optional and multivalued attributes which can also have their own attributes. Note that SIS attributes are first class citizens and they can have their own classification classes (or metaclasses) stated as attribute categories (or metacategories). ...
. Using database technology for the administration of digital libraries offers many advantages in a multi-user and distributed environment. However, conventional DBMS are not particularly suited to manage semi-structured data with heterogeneous, irregular, evolving structures as in the case of SGML documents found in digital libraries. To overcome the difficulties imposed by the rigid schema of conventional systems, several schema-less approaches have been proposed. Using instead unconstrained, extensible schemata offered by object-oriented semantic network systems, we are able both to map document specific structures as database classes, and to model the associated constraint information as integrated schema annotations. In this paper we present the benefits of this approach to create, access and process heterogeneous SGML documents, and in particular to exploit the shared semantics of evolving SGML structures. A respective application is currently being implemented in t...
... It implements an interpretation of the data model of the knowledge representation language TELOS [29] omitting the evaluation of logical rules. A formal treatment of this data model can be found in [30]. The structures and the modeling constructs of SIS allow the representation of complex thesaurus structures in an elegant and compact way. ...
The availability of central reference information as thesauri is critical for correct intellectual access to distributed databases,
in particular to digital collections in international networks. There is a continuous raise in interest in thesauri, and several
thesaurus management systems have appeared on the market. The issue, how to integrate effectively such central resources into
a multitude of client systems and to maintain the consistency of reference in an information network has not yet been satisfactorily
solved. We present here a method and an actual thesaurus management system, which is specifically designed for this use, and
implements the necessary data structures and management functions. The system handles multiple multilingual thesauri and can
be adapted to all semantic thesaurus structures currently in use. Consistency-critical information is kept as history of changes
in the form of backward differences. The system has been installed at several sites in Europe.
... The Semantic Index System (SIS) [24] is a persistent storage system based on the object-oriented semantic network data model Telos [30]. SIS-Telos data model [5] provides: unbounded classification hierarchy (metaschemata see schemata as data and allow to develop a schema under this specific discipline) multiple instantiation (one object-class can be instance of more than one classes using the attributes of all its classes-metaclasses), multiple inheritance, as well as optional and multivalued attributes which can also have their own attributes. Note that SIS attributes are first class citizens and they can have their own classification classes (or metaclasses) stated as attribute categories (or metacategories). ...
Using database technology for the administration of digital libraries offers many advantages in a multi-user and distributed environment. However, conventional DBMS are not particularly suited to manage semi-structured data with heterogeneous, irregular, evolving structures as in the case of SGML documents found in digital libraries. To overcome the difficulties imposed by the rigid schema of conventional systems, several schema-less approaches have been proposed. Using instead unconstrained, extensible schemata offered by object-oriented semantic network systems, we are able both to map document specific structures as database classes, and to model the associated constraint information as integrated schema annotations. In this paper we present the benefits of this approach to create, access and process heterogeneous SGML documents, and in particular to exploit the shared semantics of evolving SGML structures. A respective application is currently being implemented in the context of the AQUARELLE project.
