The study of qualitative spatial reasoning methodologies involves the study of topology, orientation, distance, shape, size, etc. We need to develop methods for reasoning about lines integrating the different aspects in a common framework. In order to achieve this goal we begin by studying and making some enhancements to existing work in a separate way. Later, a common framework is applied to t...

This paper presents a formalisation and exploration of the concept of eclipse from the perspective of qualitative spatial reasoning. Building upon theories of spatial connectivity, occlusion and shadows, we show that eclipses can be described and reasoned about using mereotopological relations, and that these formalisms can be used to disprove some commonsense misconceptions about the nature of...

Sketching is often used when working out ideas. This combination of drawing and conceptual labeling is a very natural and effective form of communication and problem-solving. Creating software that can participate in sketching provides many challenges. We outline the nuSketch approach to sketch understanding, which focuses on visual and conceptual understanding instead of recognition. We summar...

We examine the spatial version of the persistence problem. In temporal reasoning, this is the problem of determining whether or not the validity of a fact at some point in time persists until another point in time, given that certain events or processes may happen in between. We show that its analog does intuitively exist in spatial reasoning, and review under the aspect of transferability to s...

In this paper a framework for the combination of qualitative and metric temporal knowledge is presented. It is intended especially for technical applications with real-time requirements and was applied to several scheduling problems. For realistic applications in such domains one has to consider uncertainty and vagueness of temporal knowledge. The proposed representation has the full expressive...