Use case diagrams are one of the key concepts in the Unified Modeling Language, but their semantics and notation have some gaps that lead to frequent misunderstandings among practitioners, even about very basic questions. In this paper we address some issues regarding the relationships in which use cases may take part. The Include and Extend relationships between two use cases have presently an...

1. Transection of the ventral nerve cord of female grasshoppers activates the rhythmical motor programme for oviposition digging. 2. Electrical stimulation of the cut nerve cord had the following effects on elicited oviposition motor activity: (i) shortand long-lasting inhibition of activity, (ii) phase resetting and (iii) modulation of burst frequency. 3. Cold saline applied to the nerve cord ...

In this paper we present an alternative to the VISITOR pattern, DYNAMIC DISPATCHER, that can be applied to extend existing software in a nonintrusive way, and which simulates covariant overriding of visit methods. It allows to express polymorphic operations through visitor classes in a more natural way than the original VISITOR pattern. Our solution DYNAMIC DISPATCHER can be applied without tou...

We want to support interactive analysis (“digging”) of large quantities of data, a requirement that arises, for example, in many scientific disciplines. Such analyses require turnaround measured in minutes or seconds. Achieving this performance can demand hundreds of computers to process what may be many terabytes of data. As the applications scale, data sets grow, and resources used increase, ...