Rodrigo Alarcón’s research while affiliated with National Autonomous University of Mexico and other places

We present a system to extract definitions from a term using the Web. Definitions are organized according to a typology and its context. The structural and functional design is described; emphasizing its relevant components: the extractor of definitional context to candidates using the Yahoo!'s BOSS API; the extractor of definitional contexts and a clustering module based on textual energy as a measure of similarity.

In this paper we present a description and evaluation of a pattern-based approach for definition extraction in Spanish specialised texts. The system is based on the search for definitional verbal patterns related to four different kinds of definitions: analytical, extensional, functional and synonimical. This system could be helpful in the development of ontologies, databases of lexical knowledge, glossaries or specialised dictionaries.

In this paper we present a description of the role of definitional verbal patterns for the extraction of semantic relations. Several studies show that semantic relations can be extracted from analytic definitions contained in machine-readable dictionaries (MRDs). In addition, definitions found in specialised texts are a good starting point to search for different types of definitions where other semantic relations occur. The extraction of definitional knowledge from specialised corpora represents another interesting approach for the extraction of semantic relations. Here, we present a descriptive analysis of definitional verbal patterns in Spanish and the first steps towards the development of a system for the automatic extraction of definitional knowledge. http://repositori.upf.edu/handle/10230/6177

Terminological work aims to identify knowledge about terms in specialised texts in order to compile dictionaries, glossaries or ontologies. Searching for definitions about the terms that terminographers intend to define is therefore an essential task. This search can be done in specialised corpus, where they usually appear in definitional contexts, i.e. text fragments where an author explicitly defines a term. We present a research focused on the automatic extraction of those definitional contexts. The methodology includes three different processes: the extraction of definitional patterns, the automatic filtering of non-relevant contexts, and the automatic identification of constitutive elements, i.e., terms and definitions. http://hdl.handle.net/10230/24631

One of the main goals of terminological work is the identification of knowledge about terms in specialised texts. In order to compile dictionaries, glossaries or ontologies, terminographers use to search definitions about the terms they intend to define. The search of definitions can be done in specialised corpus, where they usually appear in definitional contexts, i.e. text fragments where an author explicitly defines a term. In this paper we present a research focused on the automatic extraction of those definitional contexts. Our methodology includes three different processes: the extraction of definitional patterns, the automatic filtering of non definitional contexts, and the automatic identification of constitutive elements, i.e., terms and definitions.

A repository of Definitional Contexts, even more than to be conceived of as traditional corpora, is very valuable tool for lexicography. This paper describes a corpus of Definitional Contexts, from the definition of the term to the description of the applications of the corpus in lexicography. The intended applications for the work, and how these affected the corpus design, are described. In addition, the methodology for corpus building and the corpus structure are outlined, and the preliminary results of the work in progress are presented.

definitorios mediante reglas léxico-metalingüísticas, con el fin de obtener conocimiento especializado que nos permita definir términos.

From a computational linguistics point of view, specifically related to information extraction, terminology uses statistical and rule-based methods (Cabré et. al. 2001) to extract terms from specialised texts. Furthermore, terminology needs to identify the corresponding definitions of a specific term. Often, when an author introduces a new term, which is not well known to the readers, he/she provides the definition emphasising the new concept with a set of syntactic and typographical features. We thus call definitional context the structure consisting of the term, the definition and the emphatic features in a specialised text. In order to develop a tool capable of extracting definitional contexts from annotated corpora, an inventory of recurrent patterns used by authors to introduce concepts is necessary, as well as a computational linguistic technique capable of identifying concepts from specialised texts. One of the objectives of the Language Engineering Group, from the Instituto de Ingeniería, UNAM (National Autonomous University of Mexico) is to extract conceptual information from corpora. For this reason, the group is working on the study of recurrent patterns in definitional contexts, the elaboration of an annotated corpus on engineering, and the development of the tools required for conceptual information extraction. In this paper we present the process of developing a definitional context extraction tool. First, we present the minimal elements of a definitional context. Second, we define a typology of all the recurrent patterns found in definitional contexts of Spanish specialised texts. Third, we present the kinds of tagging necessary. And fourth, we briefly mention the characteristics that a search engine must have. 2 Definitional contexts Our investigation is based on previous efforts such as the systematic identification of definitions based on lexical and metalinguistic patterns (Pearson, 1998), the analysis of Explicit Metalinguistic Operations (Rodríguez, 1999) and the analysis of Knowledge-Rich Contexts (Meyer, 2001).

In order to develop an engine to extract likely definitory contexts in specialised corpus, we describe the acquisition and classification of an inventory of recurrent patterns on Disasters texts.

In specialised texts, there are some recurrent typographical and syntactic patterns that authors use to define a term. Some of these syntactic patterns are verbal predications that function as connectors between terms and definitions. In this paper we analyse the role of the verbal predications involved in definitional contexts of specialised texts in Spanish, in order to develop a system capable of extracting definitional contexts.