Antonio Villegas

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The visualization and the understanding of large conceptual schemas require the use of specific methods.These methods generate clustered , summarized or focused schemas that are easier to visualize and to understand.All of these methods require computing the importance of each entity type in the schema. In principle, the totality of knowledge defined in the(More)
—The amount of knowledge represented in the Health Level 7 International (HL7) information models is very large. The sheer size of those models makes them very useful for the communities for which they are developed. However, the size of the models and their overall organization makes it difficult to manually extract knowledge from them. We propose to(More)
Human understanding of constraint expressions (also called schema rules) in large conceptual schemas is very difficult. This is due to the fact that the elements (entity types, attributes, relationship types) involved in an expression are defined in different places in the schema, which may be very distant from each other and embedded in an intricate web of(More)
A complete conceptual schema must include all relevant general static and dynamic aspects of an information system. Event types describe a nonempty set of allowed changes in the population of entity or relationship types in the domain of the conceptual schema. The conceptual schemas of many real-world information systems that include the specification of(More)
Visualizing and understanding large conceptual schemas requires the use of specific methods. These methods generate clustered, summarized, or focused schemas that are easier to visualize and understand. All of these methods require computing the importance of each entity type in the schema. In principle, the totality of knowledge defined in the schema could(More)
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