1,721,018 research outputs found
The closure properties of Functional Flow-Based Approaches and their relevance to diagnosis
No full textDiagnosis of multiple faults with flow-based functional models: the functional diagnosis with efforts and flows approach
No full textThis paper presents the FunctionalDiagnosis with efforts and flows (FDef) approach to model-baseddiagnosis. First, it motivates our research by considering the field of functionalflow-based diagnostic techniques, pointing out some of their relevant limitations, which are overcome by FDef. Then, it summarizes and exemplifies the main FDef concepts and techniques in a tutorial way. A real-world diagnostic problem in the marine engineering domain has been used to evaluate the basic FDef engine. The paper summarizes the results of the evaluation and discusses the extensions it has prompted, i.e., the introduction of qualitative deviations of variables and the exploitation of a hierarchical representation of the functional model. The ideas proposed in FDef can be easily adapted to other flow-based modeling formalisms, such as MFM
Special Issue of Computers & Education Journal on Web3D Technologies in Learning, Education and Training
No full textAutomatic derivation of hierarchical representations for flow-based functional models
No full textFlow-based functional (FBF) approaches model a system by focusing on flows (of mass,energy, or information) and on the actions performed by components on the considered flows. In this paper, we show how these approaches are particularly suited to hierarchical representation, by proposing a general technique that automatically derives a hierarchical FBF representation in polynomial time, starting from a flat FBF model. We also briefly illustrate a diagnostic reasoning example to show the usefulness of the derived hierarchical representation. The proposed technique concentrates on a set of functional primitives which is common to all FBF approaches, and is thus applicable to any FBF approach
Interfacce in Realtà Virtuale per siti di e-commerce: linee guida, ausili alla navigazione, personalizzazione
No full textRecentemente, alcuni siti di e-commerce hanno iniziato a proporre interfacce in Realtà Virtuale (RV), che promettono di rendere l’esperienza del fare acquisti in rete più naturale, attraente e divertente per i clienti. Sfortunatamente, realizzare un interfaccia per l’e-commerce in RV non è attualmente semplice e non dà garanzie di maggior efficacia al sito. In questo articolo, prima discutiamo brevemente i vantaggi potenziali di tali interfacce, poi presentiamo le direzioni di ricerca che stiamo esplorando per costruire negozi in RV più usabili ed efficaci. Tali direzioni di ricerca mirano a (i) riformulare nel contesto RV le linee guida dei negozi fisici, (ii) sfruttare la RV per creare ausili alla navigazione utente che soddisfino sia il cliente che il venditore, (iii) personalizzare il negozio in RV per meglio riflettere i gusti, le preferenze e gli interessi del cliente. Per ogni direzione, illustriamo e discutiamo brevemente un caso di studi
Hierarchical Model-Based Diagnosis based on Structural Abstraction
No full textAbstraction 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
Adaptive Hypermedia Techniques for 3D Educational Virtual Environments
No full textBased 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
Virtual Reality stores for 1-to-1 e-commerce
No full textVirtual Reality (VR) interfaces to e-commerce sites have recently begun to appear on the Internet, promising to make the e-shopping experience more natural, attractive, and fun for buyers. Unfortunately, usability of these interfaces is a major and still unexplored issue. In this paper, we present the approach we are following to guarantee and increase the usability of VR stores, also providing two practical examples of the solutions we are studying. In particular, the last part of the paper is devoted to discuss in detail how our VR store can be extended to 1-to-1 e-commerce applications
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