Jácome Cunha

This tutorial book presents revised and extended lecture notes for a selection of the contributions presented at the International Summer School on Generative and Transformational Techniques in Software Engineering (GTTSE 2009), which was held in Braga, Portugal, in July 2009. The 16 articles comprise 7 long tutorials, 6 short tutorials and 3 participants contributions; they shed light on the generation and transformation of programs, data, models, metamodels, documentation, and entire software systems. The topics covered include software reverse and re-engineering, model driven engineering, automated software engineering, generic language technology, and software language engineering.

Developing trustworthy concurrent applications is a seemingly never ending quest, which is necessary but dicult. It is necessary because mainstream systems and applications are inherently concurrent and they are pervasive to our daily life activities. It is dicult because such systems are inherently interactive and heterogeneous, so that boundaries can hardly be established for studying subsystems in isolation.
Formal methods are a key instrument in resolving ambiguities and design reliable applications in a rigorous way. The authors overview major problems in the application of formal methods and outline how they are tackled by the papers collected in this volume.

Audiovisual perception is still an intriguing phenomenon, especially when we think about the physical and neuronal differences underlying the perception of sound and light. Physically, there is a delay of ∼3 ms/m between the emission of a sound and its arrival to the observer but, on the other hand, we know that acoustic transduction is a very fast process (∼1 ms). Conversely, light speed makes negligible the physical delay while phototransduction is quite slow (∼50 ms). Audio and visual stimuli that are temporally mismatched can be perceived as a coherent audiovisual stimulus, but a sound delay is often required to achieve a better synchrony perception. In this study, we analyze the Point of Subjective Synchrony (PSS) as a function of stimulus distance to understand if individuals take into account sound velocity or if they compensate for differences in transduction time when judging synchrony. Using an audiovisual virtual-reality environment (CAVE-Like) with Point Light Walkers (PLW) as visual stimulus and sound of steps as audio stimulus, audiovisual sequences were presented from −285 to +300 ms of audio asynchrony, at different distances from the observer (10, 15, 20, 25, 30 and 35 m), and in three different conditions which differ only in the number of visual and auditory depth cues. The results show a relation between PSS and stimulus distance congruent with the differences in propagation velocity between sound and light. Depending on the number of depth cues presented, this relation appears to be increasingly closer to a model based on compensation for these physical differences.