Andreas Walter

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Most of the current methodologies for building ontologies rely on specialized knowledge engineers. This is in contrast to real-world settings, where the need for maintenance of domain specific ontologies emerges in the daily work of users. But in order to allow for participatory ontology engineering, we need to have a more realistic conceptual model of how(More)
Ontology maturing as a conceptual process model is based on the assumption that ontology engineering is a continuous collaborative and informal learning process and always embedded in tasks that make use of the on-tology to be developed. For supporting ontology maturing, we need lightweight and easy-to-use tools integrating usage and construction processes(More)
In this paper, we present a metamodel for textual use case descriptions, structurally conforming to the UML, to specify the behavior of use cases in a flow-oriented manner. While being primarily targeted at supporting requirements engineers in creating consistent use case models, the metamodel defines a textual representation of use case behavior that is(More)
The content of image archives changes rapidly. This makes the traditional separation of ontology development and image annotation steps no longer feasible. In this paper, we present an approach, termed ImageNotion that allows for the collaborative development of domain ontologies directly by domain experts with minimal ontology experience. ImageNotion is(More)
A growing number of users in Web 2.0 based social network sites and photo sharing portals upload millions of images per day. In many cases, this leads to serious privacy threats. The images reveal not only the personal relationships and attitudes of the uploader, but of other persons displayed in the images as well. In this paper, we propose the PRIMO(More)
Semantic technologies are very helpful in improving existing systems for searching, managing and retrieving of resources, e.g. image search, book-marking or expert finder systems. They enhance these systems through background knowledge stored in ontologies. However, in most cases, resources in these systems change very fast. In consequence, they require a(More)