Paulo Nazareno Maia Sampaio

About the semantic verification of SMIL documents

The paper presents a formal approach based on the RT-LOTOS formal description technique for the semantic verification of SMIL documents. The reachability analysis of RT-LOTOS specifications provides the verification of consistency properties of a document, and later on, it also enables the generation of a valid scheduling graph for its presentation. This graph characterizes the reference behaviors for the presentation of a document. Also, some erroneous semantic interpretations of SMIL documents which are not conformant with their reference behaviors are illustrated using some currently available SMIL players.

A formal approach for the presentation of interactive multimedia documents

This paper presents the on-going work using a formal approach for the design of Interactive Multimedia Documents (IMDs) based on the RT-LOTOS formal description technique. The present work extends this approach proposing the scheduling of IMDs based on a simple and operational model obtained as a result from the reachability analysis. One important breakthrough of this model is that it is a scheduling graph that provides the control of the occurrence of non-deterministic events, such as user interactions, within valid temporal intervals so that the global synchronization constraints of the document can be fulfilled during its presentation. Further on, some scheduling policies are also presented based on this model. Finally, we introduce some characteristics of the player actually available for the presentation of IMDs based on this new model.

Revisiting the concept of hypermedia document consistency

The paper generalizes previous works of the authors by revisiting the concept of temporal consistency of hypermedia documents. This generalization relies on the distinction of internal and external non-deterministic events.

An approach for the automatic generation of RT-LOTOS specifications from SMIL 2.0 documents

The flexibility of high level authoring models (such as SMIL 2.0) for the edition of complex Interactive Multimedia Documents can lead authors, in certain cases, to specify synchronization relations which could not be satisfied during the presentation of the document, thus characterizing the occurrence of temporal inconsistencies. For this reason, we need to apply a methodology which provides the formal semantics for the dynamic behaviour of the document, consistency checking, and the scheduling of the presentation taking into account the temporal non-determinism of these documents. This paper refers to a methodology for the formal design of Interactive Multimedia Documents based on the formal description technique RT-LOTOS. In particular, this paper presents an approach applied by our methodology for the automatic translation of SMIL 2.0 documents into RT-LOTOS specifications.

An integrated environment for the presentation of consistent SMIL 2.0 documents

The utilization of Interactive Multimedia Documents (IMDs) has been largely addressed in several fields such as education, medicine, etc. since these documents can be distributed and accessed over the World-Wide-Web. In this context, the W3C standard Synchronized Multimedia Integration Language (SMIL) has been proposed for the presentation of IMDs over the Web. However, the flexibility of the temporal model of SMIL 2.0 allows the author to describe temporal synchronization relationships that potentially can not be resolved during the presentation of the document, known as temporal inconsistencies. For this reason, an approach that enables to detect and correct these inconsistencies is needed.This paper presents a formal approach for the verification, scheduling and presentation of consistent SMIL 2.0 documents based on the RT-LOTOS formal description technique. Thus, the consistency analysis of SMIL 2.0 documents is presented and some solutions are proposed in order to deal with potential state space explosion problems. Further on, some contributions are also presented concerning the scheduling and presentation of SMIL 2.0 documents based on a simple scheduling graph, called a Time Labeled Automata (TLA), derived automatically from the document formal specification. Finally, a global Java-based architecture for the implementation of a player of consistent SMIL 2.0 documents is presented.

Bringing integrated multimedia content into virtual reality environments

Most of the tools and languages for modeling Virtual Reality environments, such as VRML, X3D, Java3D, etc. do not allow the description of synchronized presentation of multimedia content inside these environments. Multimedia capabilities motivate users capturing their attention, which is actually an asset when we want to provide them with a higher degree of immersion inside Virtual Reality applications. This paper presents a robust and generic solution for the integrated presentation of different kinds of media objects inside virtual environments based on the Graphical Engine OGRE.

Scheduling and presenting interactive multimedia documents

This paper presents on-going work using a formal approach for the design of Interactive Multimedia Documents (IMDs) based on the RT-LOTOS formal description technique. This work addresses more particularly the scheduling and presentation of IMDs based on a simple scheduling graph, called TLA, which is automatically derived from the document formal specification. For this purpose we present some scheduling algorithms and some implementation aspects of the resultant TLA Player. Further on, some contributions are presented concerning the optimization of pre-fetching techniques implemented in the TLA Player. At last, we present the results of some tests performed to validate the behavior of the player.

OGRE-Multimedia: An API for the Design of Multimedia and Virtual Reality Applications

Most of the tools and languages for modeling Virtual Reality environments, such as VRML, X3D, Java3D, etc. do not provide means of describing the synchronized presentation of multimedia content inside these environments. Multimedia has demonstrated its capabilities of motivating users and capturing their attention, which is an interesting characteristic when we want to provide a higher degree of immersion inside Virtual Reality applications. This paper presents a robust and generic solution for the integrated presentation of different kinds of media objects inside virtual environments based on the Graphical Engine OGRE.

A methodology for domain dialogue engineering with the Midiki dialogue manager

Implementing robust Dialogue Systems (DS) supporting natural interaction with humans still presents challenging problems and difficulties. In the centre of any DS is its Dialogue Manager (DM), providing the functionalities which permit a dialogue to move forward towards some common goal in a cooperative interaction. Unfortunately, there are few authoring tools to provide an easy and intuitive implementation of such dialogues. In this paper we present a methodology for dialogue engineering for the MIDIKI DM. This methodology bridges this gap since it is supported by an authoring tool which generates XML and compilable Java representations of a dialogue.

Designing consistent multimedia documents: the RT-LOTOS methodology

Interactive Multimedia Documents (IMDs) are expected to satisfy temporal consistency properties in order to ensure that their synchronization constraints (temporal, logical and causal) can be respected during their presentation. If an inconsistent situation can not be detected previously, the presentation of the document can be lead to undesirable deadlocks (global or partial). In particular, the flexibility of high level authoring models (such as SMIL 2.0) for the edition of complex IMDs can lead authors, in certain cases, to specify inconsistent documents. For this reason, it is necessary to apply a methodology that provides the formal modelling for the dynamic behavior of the document, consistency checking, and the scheduling of the presentation taking into account the temporal non-determinism of these documents. This paper presents the main results of the development of a formal methodology which is based on the Formal Description Technique RT-LOTOS, and which has been successfully applied to support the design of complex SMIL 2.0 documents.