Users submit queries to an online database via its query interface. Query interface parsing, which is important for many applications, understands the query capabilities of a query interface. Since most query interfaces are organized hierarchically, we present a novel query interface parsing method, StatParser (Statistical Parser), to automatically extract the hierarchical query capabilities of query interfaces. StatParser automatically learns from a set of parsed query interfaces and parses new query interfaces. StatParser starts from a small grammar and enhances the grammar with a set of probabilities learned from parsed query interfaces under the maximum-entropy principle. Given a new query interface, the probability-enhanced grammar identifies the parse tree with the largest global probability to be the query capabilities of the query interface. Experimental results show that StatParser very accurately extracts the query capabilities and can effectively overcome the problems of existing query interface parsers.

A molecular dynamics (MD) simulation was performed on the nanocrystalline (NC) Cu with an edge notch under tensile loadings, with focus on the notch sensitivity. With the increase of notch size, the dominant deformation of material changes from the shear strain, which spreads throughout the entire sample, to a single shear band, which is induced by the stress concentration at the notch root. At the same time, the samples move from notch-insensitivity to notch-sensitivity. These findings offer significant guidelines for the application of NC Cu in engineering.