Topic maps are very powerful as they allow to organize information, but they may be very large. Intuitive visual user interfaces may significantly reduce the cognitive load of the user when working with these complex structures. Visualization is a promis ing technique for both enhancing users' perception of structure in large information spaces and providing navigation facilities. It also enabl...

Since the Topic Map standard describes a prospective knowledge-structuring model that can be used in a huge variety of knowledge domains the amount of applications utilizing this standard grew enormously. Anyhow, as far as we know, there is no distributed editor of Topic Maps available on the market, that supports an intuitive possibility to manipulate or visualize Topic Maps in the World Wide ...

This paper introduces a simple and effective chaotic system using a combination of two existing one-dimension (1D) chaotic maps (seed maps). Simulations and performance evaluations show that the proposed system is able to produce many 1D chaotic maps with larger chaotic ranges and better chaotic behaviors compared with their seed maps. To investigate its applications in multimedia security, a n...

In any communication system, including the satellite and the Internet, it is almost impossible to prevent unauthorized people from eavesdropping. When information is broadcast from a satellite or transmitted through the Internet, there is a risk of information interception. Security of image and video data has become increasingly important for many applications, including video conferencing, se...

The Sky Polarization Observatory is an experiment selected by ESA for the Early Opportunity Phase onboard the International Space Station. SPOrt is the first payload specifically designed for polarization measurements, it will provide near full sky maps of the sky polarized emission at four microwave frequencies between 22 and 90 GHz. Current design of SPOrt will be presented, together with an ...

We are facing a real challenge when coping with the continuous acceleration of scientific production and the increasingly changing nature of science. In this article, we extend the classical framework of co-word analysis to the study of scientific landscape evolution. Capitalizing on formerly introduced science mapping methods with overlapping clustering, we propose methods to reconstruct phylo...

absTraCT Organizational memories play a significant role in knowledge management, but several challenges confront their use. Artifacts of OM are many and varied. Access and use of the stored artifact are influenced by the user's understanding of these information objects as well as their context. Theories of distributed cogni-tion and the notion of community of practice are used to develop a mo...