Roberto Ranon

IS Journal 2007 Journal Article

Adaptive Hypermedia Techniques for 3D Educational Virtual Environments

• Luca Chittaro
• Roberto Ranon

Based on a well-known adaptive hypermedia framework, the proposed system creates a 3D educational virtual environment that selects and personalizes interactive learning content for users. In EVEs, users not only see concepts visualized, but they can perform tasks in a suitable fictional world or a real-world reproduction. Moreover, compared to 2D multimedia, using interactive 3D graphics lets developers create representations of subjects or phenomena that are more informative and make it possible for users to analyze a single subject from different viewpoints. In EVEs, adaptivity can play an important role in increasing both learning-process effectiveness and interface usability.

AIJ Journal 2004 Journal Article

Hierarchical model-based diagnosis based on structural abstraction

• Luca Chittaro
• Roberto Ranon

Abstraction has been advocated as one of the main remedies for the computational complexity of model-based diagnosis. However, after the seminal work published in the early nineties, little research has been devoted to this topic. In this paper, we consider one of the types of abstraction commonly used in diagnosis, i. e. , structural abstraction, investigating it both from a theoretical and practical point of view. First, we provide a new formalization for structural abstraction that generalizes and extends previous ones. Then, we present two new different techniques for model-based diagnosis that automatically derive easier-to-diagnose versions of a (hierarchical) diagnosis problem on the basis of the available observations. The two proposed techniques are formulated as extensions of the well-known Mozetic's algorithm [I. Mozetic, Hierarchical diagnosis, in: W. H. L. Console, J. de Kleer (Eds.), Readings in Model-Based Diagnosis, Morgan Kaufmann, San Mateo, CA, 1992, pp. 354–372], and experimentally contrasted with it to evaluate the obtained efficiency gains.

ECAI Conference 1998 Conference Paper

The Closure Properties of Functional Flow-Based Approaches and Their Relevance to Diagnosis

• Roberto Ranon