Welcome to the fifth and last regular issue in 2015. Looking back over all issues, we have had a great variety of highly relevant research covered. This would not be possible without the marvelous support from the consortium's institutions and the high quality reviews and recommendations by the members of the editorial board.

In the fifth issue, it is my great pleasure to introduce 7 papers from 8 countries. In a collaborative work between researchers from United Kingdom and India, Neil Buckley, Atulya K. Nagar, and Subramanian Arumugam proposed a visual cryptography approach that works directly on intermediate grayscale values per colour channel and demonstrates real-valued basis matrices for this purpose. In an international research collaboration, Cristian Calude from New Zealand, Rūsiņš Freivalds from Latvia, and Sanjay Jain and Frank Stephan from Singapore discuss their research on the deterministic frequency pushdown automata, proving in this context the existence of a deterministic context-free language. Rosario Gil Ortego and Juan Antonio Gil Pascual from Spain outline their novel approach on the conceptual evaluation of massive open online courses through pathfinder associative networks. Shantanu Pal from United Kingdom explores in his paper the emergence of extending mobile cloud platforms using opportunistic networks. Jim Scullion, Gavin Baxter, and Mark Stansfield from United Kingdom review in a primarily quantitative empirical study whether the use of a 3D virtual world environment could support the concept of self-efficacy for computing undergraduate students. Pengfei Sun, Philippe Bon, and Simon Collart-Dutilleul from France introduce their work on the joint development of coloured Petri Nets and the B method in critical systems. Last but not least, Steffen Wendzel and Carolin Palmer from Germany link in their research the field of creativity and network steganographic research by proposing a framework and a metric to help evaluating the creativity bound to a given hiding technique.

Enjoy reading!

Cordially,

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