Showing papers on "Semantic Web Stack published in 1989"

The Unified Medical Language System. the Umls Semantic Network: The UMLS Semantic Network

Abstract: The UMLS network of semantic types is one component of NLM's evolving Unified Medical Language System. This paper discusses the role of the semantic network in the overall system, then describes the evolution and current status of the network, and, finally, concludes with a discussion of plans for further development.

Efficient Organization of Semantic Databases

Abstract: This paper argues that semantic data models can have potentially more efficient implementations than the conventional data models. As a step towards realization of this potential, the paper proposes an efficient storage structure for semantic databases.

A graphical query language for semantic data models

Abstract: This paper presents a graphical query language for semantic data models. This language is based on a generic semantic model. It is integrated in the CANDID system, which is a graphical interface fur the manipulation of databases. Any schema is represented by a graph divided into families of object types. The graphical query language makes it possible to express a request by describing with a graph an object solution of the request. A request is sometimes expressed in several stages. A stage corresponds to the expression of a simpler subrequest. This language is also characterized by the absence of boolean operators and quantifiers, which are replaced by manipulations on Venn diagrams. Since a request in fact defines derived elements, almost all of a request can be incorporated into the schema. CANDID has been designed to be adapted to any DBMS which has deduction mechanisms.

Using exceptions in a semantic network for a natural language application.

Abstract: This paper presents the advantages of using a semantic network with default and exception abilities for a specific problern in language processing. More precisely, we show that the features of this semantic network provide an adequate representation of texts expressing a generat rule and its exceptions. General Statements are usually expressed in natural language by the presence of some specific words, and they occur frequently in our application domain. Our research is effectively integrated in a whole project which is an interactive user-aided tool for the description of requirements including the use of graphics and textual comments. The general cases of treatments are represented by semantic rules which are not strict and admit exceptions. The inferences supported by the network are justified by an interpretation in default logic.

Modelling exceptions in semantic database and knowledge-based systems

Abstract: Exception handling has received much attention in several areas recently. In this paper, we accomodate exceptions in a semantic network model using an object-oriented approach. First, the semantic model is adequately described to allow the introduction of exceptions. Then the categories of exceptions in the model are examined. An Object-Property diagram is introduced to model the exceptions. This paper attempts to provide an alternative and better approach in handling exceptions for semantic network models. Specifically, we describe previous work done on exception handling on semantic models and introduce our proposed approach. We show how our model addresses the limitations of the previous approach as well as providing more leverage to the system.