Linguistische und semantische Annotation eines Zeitungskorpus

Dieser Artikel beschreibt das Vorgehen beim automatischen inkrementellen Aufbereiten eines rohen Textkorpus mit linguistischer und semantischer Information. Es wird gezeigt, wie das Erkennen von Eigennamen hilft, die Wortartenkategorisierung und partielle syntaktische Analysen zu verbessern. Eine Evaluation über ca. 1000 Sätze zeigt die Stärken und Schwachpunkte der verschiedenen Erkenner auf

Heterogeneity and standardization in data, use, and annotation : a diachronic corpus of German

This paper describes the standardization problems that come up in a diachronic corpus: it has to cope with differing standards with regard to diplomaticity, annotation, and header information. Such highly heterogeneous texts must be standardized to allow for comparative research without (too much) loss of information

NEUPHILOLOGISCHE FAKULTÄT RUPRECHT-KARLS-UNIVERSITÄT HEIDELBERG

1.3. Null Instantiation.............................................................................................................

Normalization And Matching Of Chemical Compound Names

We have developed ChemHits (http://sabio.h-its.org/chemHits/), an application which detects and matches synonymic names of chemical compounds. The tool is based on natural language processing (NLP) methods and applies rules to systematically normalize chemical compound names. Subsequently, matching of synonymous names is achieved by comparison of the normalized name forms. The tool is capable of normalizing a given name of a chemical compound and matching it against names in (bio-)chemical databases, like SABIO-RK, PubChem, ChEBI or KEGG, even when there is no exact name-to-name-match

From surface dependencies towards deeper semantic representations [Semantic representations]

In the past, a divide could be seen between ’deep’ parsers on the one hand, which construct a semantic representation out of their input, but usually have significant coverage problems, and more robust parsers on the other hand, which are usually based on a (statistical) model derived from a treebank and have larger coverage, but leave the problem of semantic interpretation to the user. More recently, approaches have emerged that combine the robustness of datadriven (statistical) models with more detailed linguistic interpretation such that the output could be used for deeper semantic analysis. Cahill et al. (2002) use a PCFG-based parsing model in combination with a set of principles and heuristics to derive functional (f-)structures of Lexical-Functional Grammar (LFG). They show that the derived functional structures have a better quality than those generated by a parser based on a state-of-the-art hand-crafted LFG grammar. Advocates of Dependency Grammar usually point out that dependencies already are a semantically meaningful representation (cf. Menzel, 2003). However, parsers based on dependency grammar normally create underspecified representations with respect to certain phenomena such as coordination, apposition and control structures. In these areas they are too "shallow" to be directly used for semantic interpretation. In this paper, we adopt a similar approach to Cahill et al. (2002) using a dependency-based analysis to derive functional structure, and demonstrate the feasibility of this approach using German data. A major focus of our discussion is on the treatment of coordination and other potentially underspecified structures of the dependency data input. F-structure is one of the two core levels of syntactic representation in LFG (Bresnan, 2001). Independently of surface order, it encodes abstract syntactic functions that constitute predicate argument structure and other dependency relations such as subject, predicate, adjunct, but also further semantic information such as the semantic type of an adjunct (e.g. directional). Normally f-structure is captured as a recursive attribute value matrix, which is isomorphic to a directed graph representation. Figure 5 depicts an example target f-structure. As mentioned earlier, these deeper-level dependency relations can be used to construct logical forms as in the approaches of van Genabith and Crouch (1996), who construct underspecified discourse representations (UDRSs), and Spreyer and Frank (2005), who have robust minimal recursion semantics (RMRS) as their target representation. We therefore think that f-structures are a suitable target representation for automatic syntactic analysis in a larger pipeline of mapping text to interpretation. In this paper, we report on the conversion from dependency structures to fstructure. Firstly, we evaluate the f-structure conversion in isolation, starting from hand-corrected dependencies based on the TüBa-D/Z treebank and Versley (2005)´s conversion. Secondly, we start from tokenized text to evaluate the combined process of automatic parsing (using Foth and Menzel (2006)´s parser) and f-structure conversion. As a test set, we randomly selected 100 sentences from TüBa-D/Z which we annotated using a scheme very close to that of the TiGer Dependency Bank (Forst et al., 2004). In the next section, we sketch dependency analysis, the underlying theory of our input representations, and introduce four different representations of coordination. We also describe Weighted Constraint Dependency Grammar (WCDG), the dependency parsing formalism that we use in our experiments. Section 3 characterises the conversion of dependencies to f-structures. Our evaluation is presented in section 4, and finally, section 5 summarises our results and gives an overview of problems remaining to be solved

Ontologiebasierter Forschungsführer für die Bildungsforschung

Dieser Beitrag beschreibt das Vorhaben, Semantic Web-Technologien für den Aufbau eines ontologiebasierten Forschungsführers einzusetzen. Heterogene, verteilte Datenquellen des Informationszentrums Bildung sollen auf diese Weise semantisch integriert, angereichert und über entsprechende Recherchemöglichkeiten zugänglich gemacht werden. Die einzelnen Schritte zur Umsetzung des geplanten Projekts werden vorgestellt, wobei insbesondere auf zu erwartende Mehrwerte gegenüber der aktuellen Datenquellennutzung eingegangen wird. (DIPF/Autor).This paper elaborates on the objective to use semantic web technologies for the implementation of an ontology based research guide. It aims at a semantic integration and enrichment of heterogeneous, distributed data sources of the Information Center for Education, thus making them accessible through appropriate retrieval functionalities. The individual steps of the planned project are presented with a particular focus on the added value that can be expected in comparison with the current use of the data sources. (DIPF/Author)