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This paper presents a novel data structure, called Event-centric Composable Queue (ECQ), a basic building block of a new scalable composite event monitoring (CEM) framework, SCEMon. In particular, we focus on the scalability issues when large numbers of CEM queries and event sources exist in upcoming CEM environments. To address these challenges effectively, we take an event-centric sharing approach rather than dealing with queries and sources separately. ECQ is a shared queue, which stores incoming event instances of a primitive event class. ECQs are designed to facilitate efficient shared evaluations of multiple queries over very large volumes of event streams from numerous event sources. ECQs are composable and form a single shared network within which multiple queries are simultaneously evaluated. In this paper, we present efficient shared processing techniques operating on top of the proposed shared ECQ network. The performance evaluation shows that the proposed approach achieves a high level of scalability compared to conventional separate processing approaches in large-scale CEM environments.

Media-rich ubiquitous distributed media processing workflow systems continuously sense users' needs, status, and the context, filter and fuse a multitude of real-time media data, and react by adapting the environment to the user. One challenge facing these systems is that they need to process real-time data arriving continuously from the sensors and data rates and qualities may vary dramatically. Thus, reducing the amount of unqualified data objects that need to be processed within the underlying media processing workflows can enhance the performance significantly. In this paper, we first focus on the prediction of the output qualities at the actuator, especially in the presence of fusion operators in the workflow. We then present quality-aware early object elimination schemes to enable informed resource savings in continuous real-time media processing workflow middleware.

Basic message processing tasks, such as well-formedness checking and grammar validation, can be off-loaded from the service providers' own infrastructures. To enable effective off-loading of processing tasks, we introduce the Prefix Automata SyStem - PASS, a middleware architecture which distributively processes XML payloads of Web service SOAP messages during their routing towards Web servers. PASS is based on a network of automata, where PASS-nodes independently but cooperatively process parts of the SOAP message XML payload.