Thomas Heimrich

Enhancing ECA Rules for Distributed Active Database Systems

ECA (event/condition/action) rules have been developed for central active database systems. In distributed active database systems the problem of inaccessibility of partial systems raises and thus the undecidability of ECA conditions referring to remote systems. This work proposes an enhancement of ECA rules for distributed active database systems to react also in the case of inaccessibility and undecidability. Therefore, the ECA evaluation will be enhanced to a strict function with the inaccessibility state O and a new alternative action AA enriches the classical ECA rules. The advantages and the usage of this approach are shown by an example of maintaining data consistency in distributed active database systems.

Modelling and streaming spatiotemporal audio data

In this paper, we describe a special application domain of data management – the production of high-quality spatial sound. The IOSONO system, developed by Fraunhofer IDMT, is based on the wave field synthesis. Here, a large number of loudspeakers is installed around the listening room. A rendering component computes the signal for each individual speaker from the position of the audio source in a scene and the characteristics of the listening room. So, we can achieve the impression that sound sources are on specific positions in the listening room.