This study investigates the role played by individual spatial scales in determining the apparent brightness of greyscale patterns. We measured the perceived difference in brightness across an edge in the presence of notch filtering and high-pass filtering for two stimulus configurations, one that elicits the perception of transparency and one that appears opaque. For both stimulus configuration...

Completion-based algorithms can be employed for computing the least common subsumer of two concepts up to a given role-depth, in extensions of the lightweight DL EL. This approach has been applied also to the probabilistic DL Prob-EL, which is variant of EL with subjective probabilities. In this paper we extend the completion-based lcscomputation algorithm to nominals, yielding a procedure for ...

s or to the complete newspaper corpus. This raises the question of whether better results might have been obtained if the complete data sets had been used. In principle, more data might imply more power. At the same time, more data also entails the risk of more noise. At least for our af data, enlarging the complement leads to worse performance. When we allow any sentence that contains af in ou...

Methods for computing the least common subsumer (lcs) are usually restricted to rather inexpressive DLs whereas existing knowledge bases are written in very expressive DLs. In order to allow the user to re-use concepts defined in such terminologies and still support the definition of new concepts by computing the lcs, we extend the notion of the lcs of concept descriptions to the notion of the ...