Active database systems are a current focus of considerable research interest, as a means of supporting a range of tasks including constraint enforcement, real-time applications and derived data management. However, although many diierent proposals have been made for active rule systems, such proposals are normally described in an informal manner, which makes it diicult to understand how diiere...

background bladder reconstruction in the pediatric population is challenging for many reasons, including perioperative complications and readmissions. objectives on a national scale, determine readmission rates at 30, 60 and 90 days after bladder reconstruction in a pediatric population over a 7-year period, evaluating the influence of hospital and patient-specific variables. patients and metho...

This paper describes how database systems can use and exploit a cost-effective active storage hierarchy. By active storage hierarchy we mean a database system that uses all storage media (i.e. optical, tape, and disk) to store and retrieve data and not just disk. We describe and emphasize the active part, whereby all storage types are used to store raw data that is converted to strategic busine...

Event detection is the rst and the most important step for Event-Condition-Action (ECA) rule execution in active database systems. Composite event detection is not easy for most existing active database systems. In this paper, a Conditional Colored Petri Net model (CCPN) is proposed for composite events speci cation and detection. Composite events are detected by checking composite transition e...

Event-condition-action (or ECA) rules are used to capture active capability. While a number of research prototypes of active database systems have been built, ECA rule capability in Relational DBMSs is still very limited. In this paper, we address the problem of turning a traditional database management system into a full-fledged active database system without changing the underlying system. Th...

Trend analysis and forecasting applications (e.g., securities trading, stock market, and after-the-fact diagnosis) need event detection along a moving time window. Event-driven approaches using a push-paradigm play a significant role in many real-world applications since changes detected are crucial for these applications. In active databases that provide push-paradigm, an event was defined to ...

Integrating multimedia into real-time control applications requires careful consideration. The impact of the system support needed to meet the soft real-time constraints of multimedia on meeting the hard deadlines of the control application is of paramount concern. We propose that integrated resource models and reeective real-time kernels can provide the basis for the needed solutions. Features...

AMOS (Active Mediators Object System) is an architecture to model, locate, search, combine, update, and monitor data in information systems with many work stations connected using fast communication networks. The approach is called active mediators, since it introduces an intermediate level of ‘mediator’ software between data sources and their use in applications and by users, and since it supp...

We present a formal framework that can be used to specify and study a number of different semantics for rule execution in active databases. We shall consider the core of several active rule languages that are already available (e.g., Ariel, Starburst and HiPAC) but whose rule execution is specified only by informal descriptions. The framework is based on a generic active rule language and relie...