It is a pleasure to introduce the forth regular issue of the volume 18. Authors from nine countries present in eight papers a broad variety of research aspects of computer science from basic to application-oriented research. I thank all reviewers involved in the evaluation process of these articles for their support.

Antonio L. Bajuelos, Santiago Canales and Gregorio Hernandez from Spain introduce approximate solutions to solve a new class of Art Gallery Problems inspired by wireless localization. Also in the domain of mobile computing, Alton Y.K. Chua and Radhika Shenoy Balkunje from Singapore focuse on a study of gamification for teaching Software Project Management. A technique for behavioral and temporal pattern detection within financial data - where the required information is only partially visible - is covered by Doron Drusinsky from the USA. Wojciech Frączek, Wojciech Mazurczyk and Krzysztof Szczypiorski from Poland present in their paper multilevel steganography, which defines a new concept for hidden communication in telecommunication networks. In the collaborative work of Jörg Keller from Germany and Christoph W. Kessler and Rikard Hultén from Sweden, the authors report their research on optimized on-chip-pipelining for memory-intensive computations on multi-core processors. Alexander Meduna and Petr Zemek from the Czech Republic introduce controlled pure grammar systems. An enhanced version of software cost modelling and estimation by using artificial neural networks is reported byEfi Papatheocharous and Andreas S. Andreou from Cyprus. Focusing on aspects of the Internet protocol suite, Henna Suomi, Kalevi Kilkki and Heikki Hämmäinen from Finland report on the research of a model for assessing the value of the end-to-end multipath protocols from the end user perspective.

Enjoy reading!

Cordially,

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