Right at the beginning of the summer in the northern hemisphere we are happy to announce seven high quality papers in the third regular issue of volume 18. In this issue we cover interesting contributions in a great variety of subjects of computer science from more basic to application-oriented research.

Robert Bucki from Poland and Petr Suchánek from Czech Republic cover e-commerce systems research by focusing on customer-oriented model of the e-commerce system and deal with logistic optimization and simulations.

Marijana Despotović-Zrakić, Dusan Barać, Zorica Bogdanović, Branislav Jovanić and Bozidar Radenković from Serbia contribute in the field of e-education by a new web application for teaching discrete simulation called FONWEBGPSS which enables creating, storing and executing discrete system simulation models in GPSS language.

In the same subject domain of e-education, Rafael Duque and Crescencio Bravo from Spain, and Lars Bollen and Anjo Anjewierden from the Netherlands contribute research on how to automate the analysis of problem-solving activities in learning environments.

Jens Hellmers, Jörg Thomaschewski, Eva-Maria Holt and Thomas Wriedt from Germany focus in their research on usability evaluation methods for a non-commercial scientific Internet information portal.

Marija Jovic and Dusan Milutinovic from Serbia, and Anton Kos and Saso Tomazic from Slovenia contribute on e-commerce research, specifically by dealing with customers' behavior in an online environment studying the effect of different online product presentation strategies on the customer's choice.

Ester Martínez-Martín, M. Teresa Escrig and Angel P. del Pobil from Spain focusse on spatio-temporal reasoning by introducing an easy-to-use framework that integrates and solves the reasoning process of all qualitative models based on intervals.

Finally, Cao Mukun from China and Melody Y. Kiang from the USA contribute in the field of intelligent multi-agent systems by a Belief-Desire-Intention (BDI) agent architecture for multi-strategy selection in automated negotiation.

As usually, please allow me to gratefully thank the members of our editorial board for their support resulting in another high quality issue for our research community. I'd also like to acknowledge the support of a number of researchers who are not members of the J.UCS editorial board but who nevertheless volunteered to review articles that were submitted to our journal. Last but not least, I'd also like to thank all reviewers who reviewed articles that did not make it to publication for their valuable help.

Finally, I'd like encourage authors to submit high-quality articles to our journal. Open access and broad readership guarantee a high visibility of articles published in our journal.

Enjoy reading!

Cordially,

Christian Gütl, Managing Editor
Graz University of Technology, Graz, Austria
Email: cguetl@iicm.edu