Jürgen Schlegelmilch

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With continuously growing numbers of applications, enterprises face the problem of efficiently managing the assignment of access permissions to their users. On the one hand, security demands a tight regime on permissions; on the other hand, users need permissions to perform their tasks. Role-based access control (RBAC) has proven to be a solution to this(More)
While the importance of multi-tier architectures for enterpriseinformation systems is widely accepted and theirbenefits are well published, the systematic migration frommonolithic legacy systems toward multi-tier architectures isknown to a much lesser extent. In this paper we present apattern on how to re-use elements of legacy systems withinmulti-tier(More)
The transition from traditional paper libraries to digital libraries enables new strategies for the use and maintenance of artifact collections. Distributed software development can be regarded as a special case of digital library utilization, where developers or groups of developers are working on the same software geographically dispersed in time zones(More)
Common object models select method implementations based on the class of the receiver. If an object belongs to several classes, more than one implementation is applicable for a method call. We present a conflict resolution strategy to get exactly one implementation per call. This is achieved by adding derived classes with method redefinitions.
With object-orientation, we model the world with objects and group objects with similar properties into classes. There are then two ways to build up a hierarchy of classes: extension adds new properties to create a subclass, while constraining restricts the values of existing properties. Programming languages support only subclassing by extension, but(More)