To enable ontology reuse, the Web Ontology Language (OWL) allows an ontology Kv to import an ontology Kh. To reason with such a Kv , a reasoner needs physical access to the axioms of Kh. For copyright and/or privacy reasons, however, the authors ofKh might not want to publish the axioms of Kh; instead, they might prefer to provide an oracle that can answer a (limited) set of queries over Kh, th...

We consider the problem of computing the complete answer to a query when there is limited access to relations, i.e., when binding patterns require values to be specified for certain attributes in order to retrieve data from a relation. This problem is common in information-integration systems, where heterogeneous sources have diverse and limited query capabilities. A query is stable if for any ...

Open answers in questionnaires contain valuable information that is very time-consuming to analyze manually. We present a method for hypothesis generation from questionnaires based on text clustering. Text clustering is used interactively on the open answers, and the user can explore the cluster contents. The exploration is guided by automatic evaluation of the clusters against a closed answer ...

We consider the problem of real-time communication with delay constraints. In earlier work it has been shown that a certain weighted-debt policy is feasibility-optimal in the sense that if any scheduling policy can satisfy the throughput-with-deadline requirements of all the clients, then the weighted-debt policy can do so. This raises the interesting question: Why is it that a periodic static ...

We consider the problem of scheduling m periodic tasks on n; n < m; identical processors. Our main contribution is to show that the condition n, where is the total density of the task set, is a suucient condition for scheduling the m tasks such that no deadlines are ever missed. We start with a novel representation of the periodic task scheduling problem as a maximum network ow problem. The str...

When executing different real-time applications on a single processor system, one problem is how to compose these applications and guarantee at the same time that their timing requirements are not violated. A possible way of composing applications is through the resource reservation approach. Each application is handled by a dedicated server that is assigned a fraction of the processor. Using t...

Preferences are useful when the space of feasible solutions of a given problem is dense but not all these solutions are equivalent w.r.t. some additional requirements. In this case, the goal is to find feasible solutions that most satisfy these additional requirements. In order to represent preferences, in this paper we use an extension of ordered disjunction programs. Ordered disjunction is an...

Layout design problem is one of the useful field of study used to increase the efficiency of sources in organizations. In order to achieve an appropriate layout design, it is necessary to define and solve the related nonlinear programming problems. Therefore, using computer in solving the related problems is important in the view of the researchers of this area of study. However, the designs pr...