Active database systems require facilities to specify triggers that fire when specified events occur. We propose a language for specifying composite events as eveti expressions, formed using event operators and events (primitive or composite). An event expression maps an event history to anothe-r event history that contains only the events at which the event expression is “satisfied ” and at which the trigger should 6re. We present several examples illustrating how quite complex event specifications are possible using event expressions. In addition to the basic event operators, we also provide facilities that make it easier to specify composite events. “Pipes ” allow users to isolate sub-histories of interest. “Correlation variables ” allow users to ensure that different parts of an event expression are satisfied by the same event,

Abstract- Embedded assertions have been recognized as a potentially powerful tool for automatic runtime detection of software faults during debugging, testing, maintenance and even production versions of software systems. Yet despite the richness of the notations and the maturity of the techniques and tools that have been developed for programming with assertions, assertions are a development tool that has seen little widespread use in practice. The main reasons seem to be that (1) previous assertion processing tools did not integrate easily with existing program-ming environments, and (2) it is not well understood what kinds of assertions are most effective at detecting software faults. This paper describes experience using an assertion processing tool that was built to address the concerns of ease-of-use and effective-ness. The tool is called APP, an Annotation PreProcessor for C programs developed in UNIX-based development environments. APP has been used in the development of a variety of software systems over the past five years. Based on this experience, the paper presents a classification of the assertions that were most effective at detecting faults. While the assertions that are described guard against many common kinds of faults and errors, the very commonness of such faults demonstrates the need for an explicit, high-level, automatically checkable specification of required behavior. It is hoped that the classification presented in this paper will prove to be a useful first step in developing a method of programming with assertions. Index Terms-Anna, APP, assertions, C, consistency checking, formal specifications, formal methods, programming environ-

Process Support Systems (PSSs) support business organizations in modeling, improving, and automating their business process. Thanks to their ability in enacting process models, they can be used to guide people in performing their daily work and to automate the repetitive tasks that do not require human intervention. Given these potential benefits, it is surprising to observe that PSSs are not widely adopted. This is especially true in case of highly flexible and human-intensive processes such as design processes in general and software processes in particular. This fact can be explained by observing that currently available PSSs do not fulfill some crucial needs of modern business organizations. One of their major drawbacks is that they do not offer adequate mechanisms to cope with unforeseen situations. They are good at supporting business processes if all proceeds as expected, but if an unexpected situation is met, which would require to deviate from the process model, they often bec...

Most modern business activities are carried out by a combination of computerized tools and human agents. Typical examples are engineering design activities, office procedures, and banking systems. All these human-centered systems are characterized by the interaction among people, and between people and computerized tools. This interaction defines a process, whose effectiveness is essential to ensure the quality of the delivered products and/or services. To support these systems, process-centered environments and workflow management systems have been recently developed. They can be collectively identified with the term process technology. This technology is based on the explicit definition of the process to be followed (the process model ). The model specifies the kind of support that has to be provided to human agents. An essential property that process technology must exhibit is the ability of tolerating, controlling, and supporting deviations and inconsistencies of the real...

Abstract—We describe an ongoing project building a system that consists of tools and services for supporting Cyberinfrastructure based scientific research. This system, called the Semantic Research Grid (SRG), integrates a number of existing online research tools (social bookmarking, academic search, scientific databases, journal and conference content management systems) and aims to develop added-value community-building tools that leverage the semantic analysis of digital documents. We discuss the design, the overall architecture, and the current state of the implementation of SRG, and provide a roadmap of the future work in this project. Index Terms—Cyberinfrastructure based scientific research, annotation, academic search, scientific databases I

this paper. Section 3.6 briefly draws some lessons derived from the comparison of the above PSEEs, highlighting the relationship between the completeness and coherence properties, and the architecture and features of these PSEEs.

One of the most important problems at component based software development is how to manage the already developed components. Some approaches reduce this task to storing components in a repository. Nevertheless, even storing components to reuse them later is not as simple as it may seem. As the developer of components is not necessarily the user of components, we need to offer a way to guarantee the right communication among

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