Pervasive computing environments add a multitude of additional devices to our current computing landscapes. Specialized embedded systems provide sensor information about the real world or offer a distinct functionality, e.g. presentation on a "smart wall". Spontaneous networking leads to constantly changing availability of services. This requires middleware support to ease application development. Additionally, we argue that an extensible middleware platform covering small embedded systems to full-fledged desktop computers is needed. Such a middleware should provide easy-to-use abstractions to access remote services and device-specific capabilities. We present a micro-broker-based approach which meets these requirements by allowing uniform access to device capabilities and services through proxies and the integration of different interoperability protocols. A minimum configuration of the middleware can be executed on embedded systems. Resource-rich execution environments are supported by the extensibility of the middleware.

This work introduces a highly constrained school timetabling problem which was modeled from the requirements of a German high school. The concept for solving the problem uses a hybrid approach. On the one hand an evolutionary algorithm searches the space of all permutations of the events from which a timetable builder generates the school timetables. Those timetables are further optimized by local search using specific mutation operators. Thus, only valid (partial) timetables are generated which fulfill all hard constraints.