The usage of RFID and sensing technologies in supply chain management applications requires the automatic conversion of large amounts of raw data into manageable business process information. This has led to many performance and scalability issues in existing RFID infrastructures. We present an approach to alleviate these shortcomings based on a flexible system architecture that partially migrates business data processing towards the periphery.

The existing Web service flow (WS-flow) technologies enable both static and dynamic binding of participating Web services (WSs) on the process model level. Adaptability on per-instance basis is not sufficiently supported and therefore must be addressed to improve process flexibility upon changes in the environment. Ad-hoc process instance changes can be enabled by swapping participating WS instances, by modifying port types of the partners to be invoked, and by changing process logic. In this work, we address the problem of dynamic binding of WSs to WS-flow instances at run time, i.e. the ability to exchange a WS instance participating in a WS-flow instance with an alternative one. The problem is additionally complicated by the fact that the execution of a process depends on its deployment. We describe the "find and bind" mechanism, and we show its representation as a BPEL extension. We discuss the benefits that could be gained and the disadvantages it brings in. The mechanism extends and improves the existing process technologies. It facilitates a precisely controlled policy-based selection of WSs at run time and also provides for process instance repair, while maintaining simplicity. We also discuss a prototypical implementation of the presented functionality.

Many interesting application systems, ranging from workflow management and CSCW to air traffic control, are event-driven and time-dependent and must interact with heterogeneous components in the real world. Event services are used to glue together distributed components. They assume a virtual global time base to trigger actions and to order events. The notion of a global time that is provided by synchronized local clocks in distributed systems has a fundamental impact on the semantics of event-driven systems, especially the composition of events. The well studied 2g-precedence model, which assumes that the granularity of global time-base g can be derived from a priori known and bounded precision of local clocks may not be suitable for the Internet where the accuracy and external synchronization of local clocks is best effort and cannot be guaranteed because of large transmission delay variations and phases of disconnection. We introduce a mechanism based on NTP synchronized local clocks with global reference time injected by GPS time servers. We agree that timestamps of events can be related to global reference time with bounded accuracy and propose that event timestamps are modeled using accuracy intervals. We present algorithms for event composition and event consumption which make use of accuracy interval based timestamping and illustrate the problems that arise due to inaccuracy and message transmission delays.

Presents a new approach to user interface customization in geographic information systems (GIS). This approach is based on the integration of three main components: a GIS user interface architecture; an active database mechanism; and a generic interface builder. The GIS interface architecture provides the default interface behavior, while the active system allows customization of interfaces according to the specific context. The generic interface builder relies on a library of interface objects to dynamically construct generic and customized interfaces. The main advantage of this approach is that it decreases the costs associated with developing customized GIS interfaces.