Zugl.: Linz, Universiẗat, Diss.

Zugl.: Kassel, Univ., Diss., 2006 / Download lizenzpflichtig

Zugl.: Karlsruhe, Univ., Diss., 2008 / Hergestellt on demand. - Auch im Internet unter der Adresse http://uvka.ubka.uni-karlsruhe.de/shop/isbn/978-3-86644-227-6 verfügbar

Zugl.: Karlsruhe, Univ., Diss., 2008 / Hergestellt on demand

University, Diss., 2005--Kassel. / Download lizenzpflichtig.

University, Diss., 2006--Kassel. / Download lizenzpflichtig.

Techn. Hochsch., Diss., 2005--Aachen.

Universiẗat, Diss., 2003--Saarbrücken. / Lizenzpflichtig.

In this work, we reconstructed and full characterized a dislocation microstructure that formed during an in situ micro-cantilever beam experiment. Based on this information, we were then able to infer how the dislocations propagated from the notch into the specimen. We propose using the so-called 'discrete-to-continuous' (D2C) method, which converts discrete dislocation data to continuum fields, as a means to quantify microstructures. With this method, we studied how different methods of initializing the microstructure in discrete dislocation dynamics simulations affects the resulting microstructure. We found that not considering cross-slip leads to very different microstructures, and that cross-slip results in more similar microstructures. Further, we used the continuum fields extracted via the D2C methods as input features for machine learning models for the classification of dislocation microstructures in nanoparticles. We found them to be well suited and that the combination of continuum fields is dependent on whether the microstructure is dominated by statistically stored or geometrically necessary dislocations.

The present work deals with Description Logics (DLs), a class of knowledge representation formalisms used to represent and reason about classes of individuals and relations between such classes in a formally well-defined way. We provide novel results in three main directions. (1) Tractable reasoning revisited: in the 1990s, DL research has largely answered the question for practically relevant yet tractable DL formalisms in the negative. Due to novel application domains, especially the Life Sciences, and a surprising tractability result by Baader, we have re-visited this question, this time looking in a new direction: general terminologies (TBoxes) and extensions thereof defined over the DL EL and extensions thereof. As main positive result, we devise EL++(D)-CBoxes as a tractable DL formalism with optimal expressivity in the sense that every additional standard DL constructor, every extension of the TBox formalism, or every more powerful concrete domain, makes reasoning intractable. (2) Non-standard inferences for knowledge maintenance: non-standard inferences, such as matching, can support domain experts in maintaining DL knowledge bases in a structured and well-defined way. In order to extend their availability and promote their use, the present work extends the state of the art of non-standard inferences both w.r.t. theory and implementation. Our main results are implementations and performance evaluations of known matching algorithms for the DLs ALE and ALN, optimal non-deterministic polynomial time algorithms for matching under acyclic side conditions in ALN and sublanguages, and optimal algorithms for matching w.r.t. cyclic (and hybrid) EL-TBoxes. (3) Non-standard inferences over general concept inclusion (GCI) axioms: the utility of GCIs in modern DL knowledge bases and the relevance of non-standard inferences to knowledge maintenance naturally motivate the question for tractable DL formalism in which both can be provided. As main result, we propose hybrid EL-TBoxes as a solution to this hitherto open question.