Michel Soto

Modeling Methods for Reusable and Interoperable Virtual Entities in Multimedia Virtual Worlds

Virtual Worlds are facing several challenges to become a mature technology commonly used in their numerous potential applications such as games, training, education, health and collaborative work. Main challenges are the introduction of multimedia in virtual worlds and the decrease of the cost and the required time for their design, which remains an empirical process. This paper proposes a methodology for introducing multimedia and decreasing the cost and needed time. The main interest of the proposed methodology is to provide virtual worlds with multimedia, interoperability and reusability properties. Interoperability enables virtual entities belonging to virtual worlds independently designed (i.e., no prior explicit agreement exists between theirs respective designers) to interact with each others. Reusability enables virtual worlds designers to use a virtual entity pattern initially designed for a virtual world A to be used in the design of a new virtual world B. The originality of this methodology relies on multiagent concepts and learning techniques for avoiding prior complex specifications tasks to achieve interoperability and reusability of multimedia virtual entities in virtual worlds.

Topic Maps, RDF Graphs, and Ontologies Visualization

Information retrieval in current information systems has become very difficult. These systems’ complexity is due to the large volume of data, their lack of structure, and theirmultidimensionality. The SemanticWeb Initiative, proposedbyTimBerners-Lee (2001), aims atmaking computers process datamore efficiently by adding semantics— such as definitions or relationships—between resources on the Web. The Semantic Web is not intended to replace the current Web, but to extend it. Several levels compose the SemanticWeb, thus providing several degrees of expressivity:

A semantic approach of virtual worlds interoperability

This paper presents a semantic approach to a solution of the problem of interoperability for virtual worlds. The semantics of virtual worlds and virtual entities is described using the Influence/Reaction model of multi-agent systems. The main feature of this model is to clearly separate the description of an action (performed by virtual entities) and the consequences of the action. We demonstrate how this separation is highly favourable to design virtual worlds with interoperability. We use and extend the Influence/Reaction model to quantify the semantic compatibility level between virtual worlds and then to compute the resulting behavior of virtual entities involved in an interoperability session. Nevertheless, the Influence/Reaction model can work properly for interoperability purposes only if the symbols (names) used to describe the virtual entities are identical in each virtual world. This constraint is relaxed by using the ontology concept.

Spatial Visualisation of Conceptual Data

Numerous data mining methods have been designed to help extract relevant and significant information from large datasets. Computing concept lattices allows clustering data according to their common features and making all relationships between them explicit. However, the size of such lattices increases exponentially with the volume of data and its number of dimensions. This paper proposes to use spatial pixel-oriented and tree-based visualisations of these conceptual structures in order to optimally exploit their expressivity.

Topic Maps Visualization

The standards developed in the context of the Semantic Web provide means of adding semantics to the data available on the Web. XML is a first level of semantics which allows users to structure data with regard to their content rather than their presentation. However, more semantics can be added with the Resource Description Framework (RDF) (1999) or Topic Maps (1999) standards. RDF was developed by the World Wide Web Consortium (1999) whereas Topic Maps were defined by the International Organization for Standardization (1999). The Topic Map paradigm was recently adapted to the Web by the consortium TopicMaps.Org (2001). Both RDF and Topic Maps aim at representing knowledge about information resources by annotating them.

Virtualization in systems biology: metamodels and modeling languages for semantic data integration

We examined the process of virtualization to deal with data intensive problems. Since data integration is a first-order priority in systems biology, we started developing a new method to manipulate data models through ordinary metadata transactions, i.e. by preserving the original data format stored in resources. After discussing why metamodels are made for, and the interplay of modeling languages in metamodel design, we presented a systemic metamodel-driven strategy to integrate semantically heterogeneous data.

Interoperable networked virtual environments

The interoperability between heterogeneous distributed virtual environments is one of the main problem virtual reality will have to face in the very near future. This article presents the main concepts we propose in NOVA (Networked Open Virtual Environment). These concepts are presented as a set of paradigms based on the semantics of a virtual world and its virtual entities.

A multimedia document distribution system over DQDB MANs

In this paper, we present a system architecture for supporting Real-time Multimedia Document Distribution Applications. This architecture is based on an extended version of the ODA (Office Document Architecture) standard using as communications support the IEEE 802.6 MAN Standard: an integrated services local area network (ILAN). Multimedia document delivery is performed by dynamically allocating the network bandwidth. This allocation strategy is based on the bandwidth required by the various media composing the documents. A performance analysis of the proposed bandwidth allocation scheme is given.